PUBLICATIONS 2011 - 2020
Ru-Ze Liang, Maxime Babics, Akmaral Seitkhan, Kai Wang, Paul Bythell Geraghty, Sergei Lopatin, Federico Cruciani, Yuliar Firdaus, Marco Caporuscio, David J. Jones and Pierre M. Beaujuge
Advanced Functional Materials 28, 1705464 (2019)
Akanksha Jetly, Rajesh Mehra
Optical Materials 88, 304 (2019)
Markus Regnat, Kurt P. Pernstich, Beat Ruhstaller
Organic Electronics 70, 219-226 (2019)
https://doi.org/10.1016/j.orgel.2019.04.027
Abstract:
We present an electro-optical model of a three-layer phosphorescent OLED which accurately describes the measured current efficiency and transient electroluminescence decay for different biases. Central findings are a bias-dependent emission zone, which influences light outcoupling as well as exciton quenching, and the presence of strong triplet-polaron quenching even at low bias. The measured current efficiency initially increases up to 9 V before it decreases, where the increase is found to be caused by reduced triplet-polaron quenching with holes, while the decrease is caused by a reduced light outcoupling and increased triplet-triplet annihilation. The numerical model allows identifying the individual contributions of the exciton continuity equation and explains the electroluminescence decay, which deviates significantly from a mono-exponential decay due to the dominating influence of exciton generation and quenching after the external bias is removed.
Luiz Gustavo Simão Albano, João Vitor Paulin, Luciana Daniele Trino, Silvia Leticia Fernandes, Carlos Frederico de Oliveira Graeff
Journal of Applied Polymer Science 136, 47805 (2019)
Paramaguru Ganesan, Wen-Yi Hung, Jen-Yung Tso, Chang-Lun Ko, Tsai-Hui Wang, Po-Ting Chen, Hsiu-Fu Hsu, Shih-Hung Liu, Gene-Hsiang Lee, Pi-Tai Chou, Alex K.-Y. Jen and Yun Chi
Advanced Functional Materials 2019, 1900923
Kyungnam Kang and Jungho Kim
Journal of the Korean Physical Society 74, 649 (2019)
Rita Rana and Rajesh Mehra
Journal of Electronic Materials (2019)
Youqin Zhu, Abay Gadisa, Zhengxing Peng, Masoud Ghasemi, Long Ye, Zheng Xu, Suling Zhao, and Harald Ade
Advanced Energy Materials 1900376 (2019)
Yuliar Firdaus, Vincent M. Le Corre, Jafar I. Khan, Zhipeng Kan, Frédéric Laquai, Pierre M. Beaujuge, and Thomas D. Anthopoulos
Advanced Science 1802028 (2019)
Ik Jang Ko, Hyuna Lee, Jin Hwan Park, Gyeong Woo Kim, Raju Lampande, Ramchandra Pode and Jang Hyuk Kwon
Phys. Chem. Chem. Phys. 21, 7083 (2019)
Jingyang Xiao, Minrun Ren, Guichuan Zhang, Jianbin Wang, Donglian Zhang, Linlin Liu, Ning Li, Christoph J. Brabec, Hin-Lap Yip and Yong Cao
Solar RRL 201900077 (2019)
Alfian F. Madsuha, Chuyen Van Pham, Michael Eck, Martin Neukom, and Michael Krueger
Journal of Nanomaterials, Article ID 6095863 (2019)
Zhenchao Li, Ziming Chen, Yongchao Yang, Qifan Xue, Hin-Lap Yip and Yong Cao
Nature Communications 10:1027 (2019)
https://doi.org/10.1038/s41467-019-09011-5
Abstract:
In recent years, substantial progress has been made in developing perovskite light-emitting diodes with near-infrared, red and green emissions and over 20% external quantum efficiency. However, the development of perovskite light-emitting diodes with blue emission remains a great challenge, which retards further development of full-color displays and white-light illumination based on perovskite emissive materials. Here, firstly, through composition and dimensional engineering, we prepare quasi-two-dimensional perovskite thin films with improved blue emission, taking advantages of reduced trap density and enhanced photoluminescence quantum yield. Secondly, we find a vertically non-uniform distribution of perovskite crystals in the PEDOT:PSS/perovskite hybrid film. Through modulating the position of the recombination zone, we activate the majority of quasi-two-dimensional perovskite crystals, and thus demonstrate the most efficient blue perovskite light-emitting diode to date with emission peak at 480 nm, record luminance of 3780 cd m−2 and record external quantum efficiency of 5.7%.
Simon Züfle, Rickard Hansson, Eugene A. Katz, Ellen Moons
Solar Energy 183 (2019) 234–239
https://doi.org/10.1016/j.solener.2019.03.020
https://authors.elsevier.com/c/1YiXX,tRdATFb
Abstract:
Encapsulated organic solar cells often show a burn-in behaviour under illumination. This burn-in manifests itself as a rapid performance loss followed by a much slower progression of the degradation. Here we investigate the burn-in for PCDTBT:PC70BM solar cells under a wide range of illumination intensities. We find that increasing the sunlight concentration from 1 Sun to up to 100 Suns does not change the degradation behaviour, i.e. the dependence of all principal photovoltaic parameters on the dose of solar exposure (in Sun hours). This suggests that the degradation mechanisms under solar concentration (≤100 Suns) are the same as those observed under 1 Sun. This result makes it possible to use concentrated sunlight for accelerated stability assessment of these devices. We also find that devices with PEDOT:PSS as hole transport material show a rapid drop in open-circuit voltage of around 100 mV during the first Sun hour of light exposure. By replacing PEDOT:PSS with MoO3 this initial process can be prevented and only the much slower part of the photo-degradation takes place.
Jelena Vujančević, Pavao Andričević, Anđelika Bjelajac, Veljko Đokić, Maja Popović, Zlatko Rakočević, Endre Horváth, Márton Kollár, Bálint Náfrádi, Andreas Schiller, Kondrad Domanski, László Forró, Vera Pavlović, Đorđe Janaćković
Ceramics International 45,10013 (2019)
https://doi.org/10.1016/j.ceramint.2019.02.045
Abstract:
Highly ordered, anodically grown TiO2 nanotubes on titanium supports were annealed in ammonia atmosphere in order to incorporate nitrogen doping (. 2 at.%) in the titanium oxide lattice. FESEM micrographs revealed nanotubes with an average outer diameter of 101.5 ± 1.5 nm and an average wall thickness of about 13 nm. Anatase crystals were formed inside the tubes after annealing in ammonia atmosphere for 30 min. With further annealing, rutile peaks appeared due to the thermal oxidation of the foil and rise as the duration of heat treatment was increased. The concentration and chemical nature of nitrogen in the nanotube arrays can be correlated to the optical response of dry-pressed heterojunctions of doped TiO2/CH3NH3PbI3 single crystals. The N-TiO2/perovskite heterojunction with the highest amount of interstitial nitrogen exhibited an improved photocurrent, indicating the importance of the semiconductor doping-based heterojunction optimization strategies to deliver competitive levels of halide perovskite-based optoelectronic devices to be envisioned for urban infrastructures.
Dario Di Carlo Rasi, Pieter M. J. G. van Thiel, Haijun Bin, Koen H. Hendriks, Gaël H. L. Heintges, Martijn M. Wienk, Tim Becker, Yongfang Li, Thomas Riedl, and Rene A. J. Janssen
Solar RRL 2019, 1800366
Wolfgang Tress, Konrad Domanski, Brian Carlsen, Anand Agarwalla, Essa A. Alharbi, Michael Graetzel and Anders Hagfeldt
Nature Energy 4, 568 (2019)
https://www.nature.com/articles/s41560-019-0400-8
Description:
W. Tress and co-authors characterized and analyzed the performance of an efficient perovskite solar cell (PSC) under simulated ambient conditions based on real temperature and irradiance data from selected days over one year at a location in central Europe. They find that the PSC shows only a low decrease of efficiency with elevated temperature and low light intensity, maintaining almost optimum values for ambient conditions, under which most of the solar energy is incident on the solar cell.
Meiyue Liu, Ziming Chen, Zhen Chen, Hin-lap Yip and Yong Cao
Mater. Chem. Front., 2019
https://doi.org/10.1039/C8QM00620B
Abstract:
The tandem architecture for perovskite solar cells has proven successful in promoting the development of such cells. A low-bandgap perovskite solar cell, which typically acts as a back cell, is one of the critical components for tandem perovskite solar cells. However, nowadays, highly efficient low-bandgap perovskite solar cells are mostly based on the inverted structure, which restricts the development of conventional perovskite tandem cells. Therefore, efficient low-bandgap perovskite solar cells based on the conventional structure need to be developed to further extend the availability of device architectures and interfacial materials for tandem cells. Here, by modifying the electron transport materials, we successfully demonstrated an efficient low-bandgap perovskite solar cell based on conventional structure. A ZnO/SnO2/C60-SAM tri-layer was used to engineer the energy level alignment of electron transport layers to reduce the energy loss occurring at the interface and simultaneously suppress the interfacial recombination and improve the charge extraction, resulting in a reduced open-circuit voltage loss for the device. Finally, our low-bandgap perovskite solar cells achieved a power conversion efficiency of 13.8%, which is the record result for conventional device structures to date.
Masaki Tanaka, Hiroki Noda, Hajime Nakanotani, and Chihaya Adachi
Adv. Electron. Mater. 2019, 1800708
https://doi.org/10.1002/aelm.201800708
Abstract:
The relatively short device lifetime of blue organic light‐emitting diodes (OLEDs) when compared with the lifetimes of green and red OLEDs is one of the crucial problems that must be overcome to enable practical application of these devices to full‐color OLED displays. This work focuses on the degradation phenomena of OLEDs that are based on sky‐blue thermally activated delayed fluorescence emitters and clarifies the degradation mechanisms based on spectral change of the electroluminescence, which indicates the formation of electromer emission from an electron transport layer. Additionally, it is determined that the change in the carrier balance that occurs during this degradation process can be ascribed to the formation of electron traps.
Jwo-Huei Jou, You-Ting Lin, Yu-Ting Su, Wei-Chi Song, Shiv Kumar, Deepak Kumar Dubey, Jing-Jong Shyue, Hsun-Yun Chang, Yun-Wen You, Tzu-Wei Liang
Organic Electronics 67 (2019) 222
Chenyi Yang, Ningning Liang, Long Ye, Harald Ade, Xiaotao Yuan, Jianhui Hou
Organic Electronics 68 (2019) 15
Markus Regnat, Kurt P. Pernstich, Kwon-Hyeon Kim, Jang-Joo Kim, Frank Nüesch, and Beat Ruhstaller
Adv. Electron. Mater. 1900804 (2019)
https://doi.org/10.1002/aelm.201900804
Fluorescence-based organic light-emitting diodes (OLEDs) using thermally activated delayed fluorescence (TADF) have increasingly attracted attention in research and industry. One method to implement TADF is based on an emitter layer composed of an exciplex host and a fluorescent dopant. Even though the experimental realization of this concept has demonstrated promising external quantum efficiencies, the full potential of this approach has not yet been assessed. To this end, a comprehensive electro-optical device model accounting for the full exciton dynamics including triplet harvesting and exciton quenching is presented. The model parameters are fitted to multiple output characteristics of an OLED comprising a TADF exciplex host with a fluorescent emitter, showing an external quantum efficiency of >10%. With the model at hand, an emission zone analysis and a parameter study are performed, and possible routes for further efficiency enhancement are presented.
Seong Keun Kim, Raju Lampande, and Jang Hyuk Kwon
ACS Photonics (2019)
https://doi.org/10.1021/acsphotonics.9b01155
Abstract:
To attain high efficiency and stability in a top-emission organic light-emitting diode (TEOLED), the semitransparent metal cathode must have high transmittance, low absorbance, and uniform surface properties under continuous driving conditions. However, conventional semitransparent metal electrodes have numerous fundamental issues. Here, we report an electro-optically efficient and stable semitransparent pristine thin Ag cathode configuration for the high performances of TEOLED.
Yuanbao Lin, Begimai Adilbekova, Yuliar Firdaus, Emre Yengel, Hendrik Faber, Muhammad Sajjad, Xiaopeng Zheng, Emre Yarali, Akmaral Seitkhan, Osman M. Bakr, Abdulrahman El-Labban, Udo Schwingenschlögl, Vincent Tung, Iain McCulloch, Frédéric Laquai, and Thomas D. Anthopoulos
Advanced Materials 1902965 (2019)
https://doi.org/10.1002/adma.201902965
Abstract:
The application of liquid‐exfoliated 2D transition metal disulfides (TMDs) as the hole transport layers (HTLs) in nonfullerene‐based organic solar cells is reported. It is shown that solution processing of few‐layer WS2 or MoS2 suspensions directly onto transparent indium tin oxide (ITO) electrodes changes their work function without the need for any further treatment. HTLs comprising WS2 are found to exhibit higher uniformity on ITO than those of MoS2 and consistently yield solar cells with superior power conversion efficiency (PCE), improved fill factor (FF), enhanced short‐circuit current (JSC), and lower series resistance than devices based on poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) and MoS2. Cells based on the ternary bulk‐heterojunction PBDB‐T‐2F:Y6:PC71BM with WS2 as the HTL exhibit the highest PCE of 17%, with an FF of 78%, open‐circuit voltage of 0.84 V, and a JSC of 26 mA cm−2. Analysis of the cells' optical and carrier recombination characteristics indicates that the enhanced performance is most likely attributed to a combination of favorable photonic structure and reduced bimolecular recombination losses in WS2‐based cells. The achieved PCE is the highest reported to date for organic solar cells comprised of 2D charge transport interlayers and highlights the potential of TMDs as inexpensive HTLs for high‐efficiency organic photovoltaics.
Eric A. Margulies, Pierre-Luc T. Boudreault, Vadim I. Adamovich, Bert D. Alleyne, Michael S. Weaver, Julie J. Brown
SID 2019 DIGEST
Yong Cui, Huifeng Yao, Jianqi Zhang, Tao Zhang, Yuming Wang, Ling Hong, Kaihu Xian, Bowei Xu, Shaoqing Zhang, Jing Peng, Zhixiang Wei, Feng Gao & Jianhui Hou
Nature Communications 10, 2515 (2019)
Daniele Braga, Sandra Jenatsch, Lieven Penninck, Roman Hiestand, Matthias Diethelm, Stéphane Altazin, Christoph Kirsch, Beat Ruhstaller
SID Symposium Digest of Technical Papers, 50: 953-956.
29 May 2019
doi.org/10.1002/sdtp.13083
We achieved a quantitative understanding of both electrical and optical coupling in OLED displays, by employing the simulation software LAOSS. For an AMOLED of around 300 PPI we found that the relative luminance between the addressed pixel and the neighbors can be as high as 40%, hampering significantly the quality of the final image. Similarly, in WOLEDs/CFs the light leakage to the neighboring pixels is clearly detectable, especially for wavelengths in the blue region of the spectrum.
Jafar I. Khan, Raja S. Ashraf, Maha A. Alamoudi, Mohammed N. Nabi, Hamza N. Mohammed, Andrew Wadsworth, Yuliar Firdaus, Weimin Zhang, Thomas D. Anthopoulos, Iain McCulloch, Frédéric Laquai
Solar RRL (2019)
Robin E. M. Willems, Stefan C.J. Meskers, Martijn M. Wienk, and René A. J. Janssen
J. Phys. Chem. C (2019)
Alexander J.L. Hofmann, Simon Züfle, Kohei Shimizu, Markus Schmid, Vivien Wessels, Lars Jäger, Stéphane Altazin, Keitaro Ikegami, Motiur Rahman Khan, Dieter Neher, Hisao Ishii, Beat Ruhstaller, and Wolfgang Brütting
Physical Review Applied 12, 064052 (2019)
http://dx.doi.org/10.1103/PhysRevApplied.12.064052
If not oriented perfectly isotropically, the strong dipole moment of polar organic semiconductor materials such as tris-(8-hydroxyquinolate)aluminum (Alq3) will lead to the buildup of a giant surface potential (GSP) and thus to a macroscopic dielectric polarization of the organic film.
Sudhir Kumar, Jakub Jagielski, Tommaso Marcato, Simon F. Solari, and Chih-Jen Shih
J. Phys. Chem. Lett. 2019, 10, 24, 7560-7567
https://doi.org/10.1021/acs.jpclett.9b02950
There has been a tremendous amount of interest in developing high-efficiency light-emitting diodes (LEDs) based on colloidal nanocrystals (NCs) of hybrid lead halide perovskites. Here, we systematically investigate the ligand effects on EL characteristics by tuning the hydrophobicity of primary alkylamine ligands used in NC synthesis. By increasing the ligand hydrophobicity, we find (i) a reduced NC size that induces a higher degree of quantum confinement, (ii) a shortened exciton lifetime that increases the photoluminescence quantum yield, (iii) a lowering of refractive index that increases the light outcoupling efficiency, and (iv) an increased thin-film resistivity. Accordingly, ligand engineering allows us to demonstrate high-performance green LEDs exhibiting a maximum external quantum efficiency up to 16.2%. The device operational lifetime, defined by the time lasted when the device luminance reduces to 85% of its initial value, LT85, reaches 243 min at an initial luminance of 516 cd m–2.
Matthias Diethelm, Andreas Schiller, Maciej Kawecki, Andrius Devižis, Balthasar Blülle, Sandra Jenatsch, Evelyne Knapp, Quirin Grossmann, Beat Ruhstaller, Frank Nüesch, and Roland Hany
Advanced Functional Materials 1906803 (2019)
https://doi.org/10.1002/adfm.201906803
In light‐emitting electrochemical cells (LECs), the position of the emission zone (EZ) is not predefined via a multilayer architecture design, but governed by a complex motion of electrical and ionic charges. As a result of the evolution of doped charge transport layers that enclose a dynamic intrinsic region until steady state is reached, the EZ is often dynamic during turn‐on. For thick sandwich polymer LECs, a continuous change of the emission color provides a direct visual indication of a moving EZ. Results from an optical and electrical analysis indicate that the intrinsic zone is narrow at early times, but starts to widen during operation, notably well before the electrical device optimum is reached. Results from numerical simulations demonstrate that the only precondition for this event to occur is that the mobilities of anions and cations are not equal, and the direction of the EZ shift dictates mobilitycat > mobilityan. Quantitative ion profiles reveal that the displacement of ions stops when the intrinsic zone stabilizes, confirming the relation between ion movement and EZ shift. Finally, simulations indicate that the experimental current peak for constant‐voltage operation is intrinsic and the subsequent decay does not result from degradation, as commonly stated.
Sandra Jenatsch, Simon Züfle, Paul-Anton Will, Balthasar Blülle, Martin Neukom, Simone Lenk, Sebastian Reineke, Daniele Braga, Konrad Domanski, Beat Ruhstaller
SID 2019 Digest, P-176 (2019)
https://doi.org/10.1002/sdtp.13333
Single-carrier devices are perfect model systems to extract material parameters for more complex multilayer organic light-emitting diodes (OLEDs) and to learn about charge transport and injection properties of the device. By combining simulation and measurements in steady-state and frequency domain, we obtain a set of reliable material parameters which can be used to model the multilayer OLED structure. Moreover, we can also evaluate the contact behavior and conclude that the OLED operation is limited by electron transport.
Martin T. Neukom
Dissertation, University of Augsburg, 2019
Solar energy is one of the key enabling technologies for the transition to a zero-carbon society – a necessity to mitigate global climate change. Emerging photovoltaic technologies based on novel semiconductor materials offer new disruptive applications since they can be made light-weight, flexible and in arbitrary shape and colour. A novel step response technique illustrates that the retraction of ionic charges from layer interfaces enables charge transport.
Sungho Nam, Mujeeb Ullah Chaudhry, Kornelius Tetzner, Christopher Pearson, Chris Groves, Michael C. Petty, Thomas D. Anthopoulos, and Donal D. C. Bradley
ACS Photonics (2019)
https://doi.org/10.1021/acsphotonics.9b01265
Device characterization shows that the use of P(VDF-TrFE-CTFE) leads to larger channel currents (≈2 mA) and lower operating voltages (−35 V) than for previously reported polymer based OLETs. Furthermore, the combined transparency of the dielectric and gate electrode, results in efficient bottom emission with external quantum efficiency of ≈0.88% at a luminance L ≥ 2000 cd m–2. Importantly, the resulting OLETs exhibit excellent shelf life and operational stability. The present work represents a significant step forward in the pursuit of all-solution-processed OLET technology for lighting and display applications.
Jordi Sastre, Tzu-Ying Lin, Alejandro Nicolas Filippin, Agnieszka Priebe, Enrico Avancini, Johann Michler, Ayodhya N. Tiwari, Yaroslav E. Romanyuk, and Stephan Buecheler
ACS Appl. Energy Mater., (2019)
https://doi.org/10.1021/acsaem.9b01387
Garnet Li7La3Zr2O12 (LLZO) is a promising solid-state electrolyte due to its wide electrochemical stability window and high Li-ion conductivity. This electrolyte has potential to be employed in the form of thin films for solid-state batteries, a promising approach in the quest for safer batteries with higher energy densities at lower fabrication costs. In this study, we use a scalable cosputtering process to fabricate LLZO thin films with subsequent postannealing at a temperature of 700 °C, significantly below the sintering temperatures employed in ceramic pellet processing.
Thorsten E. Umbach, Stefan Röllgen, Stefan Schneider, Heike Klesper, Anne M. Umbach, Klaus Meerholz
Adv. Eng. Mater. (2019)
https://doi.org/10.1002/adem.201900897
Organic light‐emitting diodes (OLEDS) still suffer from limited outcoupling efficiencies. In this contribution, a novel technology for the enhancement of the outcoupling efficiency of OLED devices is presented. By means of electro‐spray deposition (ESD) the active hole‐transport layer (HTL) is modified to have a reduced effective refractive index due to its porosity. A green‐emitting stack is tailored to demonstrate this effect, whereas additional haze effects are to be prevented. The introduction of a low‐index HTL results in a more efficient light extraction by a factor of 1.05 showing excellent agreement between experiment and simulation.
Akmaral Seitkhan, Marios Neophytou, Mindaugas Kirkus, Edy Abou-Hamad, Mohamed Nejib Hedhili, Emre Yengel, Yuliar Firdaus, Hendrik Faber, Yuanbao Lin, Leonidas Tsetseris, Iain McCulloch, and Thomas D. Anthopoulos
Advanced Functional Materials 1905810 (2019)
https://doi.org/10.1002/adfm.201905810
A simple approach that enables a consistent enhancement of the electron extracting properties of the widely used small-molecule Phen-NaDPO and its application in organic solar cells (OSCs) is reported. It is shown that addition of minute amounts of the inorganic molecule Sn(SCN)2 into Phen-NaDPO improves both the electron transport and its film-forming properties. Use of Phen-NaDPO:Sn(SCN)2 blend as the electron transport layer (ETL) in binary PM6:IT-4F OSCs leads to a remarkable increase in the cells’ power conversion efficiency (PCE) from 12.6% (Phen-NaDPO) to 13.5% (Phen-NaDPO:Sn(SCN)2). Combining the hybrid ETL with the best-in-class organic ternary PM6:Y6:PC70BM systems results to a similarly remarkable PCE increase from 14.2% (Phen-NaDPO) to 15.6% (Phen-NaDPO:Sn(SCN)2). The consistent PCE enhancement is attributed to reduced trap-assisted carrier recombination at the bulk-heterojunction/ETL interface due to the presence of new energy states formed upon chemical interaction of Phen-NaDPO with Sn(SCN)2. The versatility of this hybrid ETL is further demonstrated with its application in perovskite solar cells for which an increase in the PCE from 16.6% to 18.2% is also demonstrated.
Yan-Zhi Chen, Dian Luo, Chi-Haw Hsiang, Rong-Huei Yi, Ching-Hsuan Lin, Chin-Wei Lu, Shun-Wei Liu, Chih-Hao Chang, Hai-Ching Su
Organic Electronics (2019)
https://doi.org/10.1016/j.orgel.2019.105515
Enhancing device efficiencies of the blue and white light-emitting electrochemical cells (LECs) is realized by employing substrates with embedded diffusive layers containing scattering TiO2 nanoparticles (NPs). The diffusive layers can eliminate the influence of microcavity effect on the output electroluminescence (EL) spectrum and recover the intrinsic EL spectrum of the emissive layer. The emission zone positions of the blue and white LECs are estimated by fitting the measured EL spectra with the simulated EL spectra based on precisely tuned emission zone positions. Incorporating red-emitting guest dopant in the white LEC results in shifted emission zone toward the cathode due to enhanced electron trapping.
Marios Neophytou, Michele De Bastiani, Nicola Gasparini, Erkan Aydin, Esma Ugur, Akmaral Seitkhan, Floriana Moruzzi, Yasmin Choaie, Alexandra J. Ramadan, Joel R. Troughton, Rawad Hallani, Achilleas Savva, Leonidas Tsetseris, Sahika Inal, Derya Baran, Frédéric Laquai, Thomas D. Anthopoulos, Henry J. Snaith, Stefaan De Wolf, and Iain McCulloch
ACS Appl. Energy Mater. (2019)
https://doi.org/10.1021/acsaem.9b01567
Charge transport layers strongly influence the performance of perovskite solar cells (PSCs). To date, compact layers and mesoporous scaffolds of titanium dioxide have emerged as good electron transport layers (ETL), enabling record power conversion efficiencies (PCE). However, these ETLs require sintering above 400 ¡ãC, which excludes them from low-temperature applications such as flexible devices and silicon-heterojunction tandems. Furthermore, instability of TiO2 under prolonged exposure to sunlight appears to be a critical issue. Here, we present the promising characteristics of low-temperature processed strontium titanate (STO) as an ETL to realize PSCs with 19% PCE. STO is a wide bandgap transparent inorganic perovskite. Compared with other low-temperature processed interlayers, STO reduces the parasitic absorption in the ultraviolet and visible range, improves the electron transport, and greatly increases the stability of the devices, retaining ¡«80% of their initial efficiency after 1000 h of constant white light illumination.
Xiang Xu, Jingyang Xiao, Guichuan Zhang, Long Wei, Xuechen Jiao, Hin-Lap Yip, Yong Cao
Science Bulletin (2019)
https://doi.org/10.1016/j.scib.2019.10.019
Interfacial modification of ZnO electron transparent layer with a fullerene self-assembled monolayer can simultaneously improve the efficiency and photo-stability of organic solar cells by improving the charge extraction property and stabilizing the active layer morphology, leading to a state-of-the-art organic solar cell with extrapolated lifetime more than 20 years.
Moulay Ahmed Slimani
Masterthesis, Universite de Quebec, 2019
Based on current energy and environmental context, research in the photovoltaic field is growing very fast. Silicon photovoltaic (PV) cells dominate the world market. One of the reasons limiting the efficiency of silicon-based solar cells are the losses due to thermalization. multi-junction cells represent a solution to reduce these losses, but they are expensive too. The printing technique, therefore represents a viable alternative for it is a low temperature and a low-cost technique. Moreover, it can be realized on flexible devices and with unlimited raw material. The objectives of this thesis are thus to firstly realize perovskite solar cells using the Slot Die printing technique and then to optimize it to optimize a 4-terminal (4T) tandem silicon/perovskite cell. A simulation study by SETFOS (Semiconducting Emission Thin Film Optics Simulation) was made to understand and optimize the effect of thickness, mobility of charge carriers and bands energy on the efficiency of the perovskite solar cell. Then, a characterization of the absorption coefficient of other layers inside the cells were made using Lambda 750 UV / Vis / NIR and X-ray diffraction technique (XRD) were used to optimize the temperature and the annealing time of the perovskite film. The last part of this work was reserved to the study of the effects of the layers of the perovskite cell on the absorption of the mono-crystalline silicon cell. This experimental study allowed us to optimize the layers of the perovskite solar cell and to evaluate the feasibility of having a perovskite/silicon tandem solar cell.
Miaosheng Wang, Yi-Hsuan Huang, Kai-Siang Lin, Tzu-Hung Yeh, Jiashun Duan, Tzu-Yu Ko, Shun-Wei Liu, Ken-Tsung Wong, and Bin Hu
Advanced Materials, 1904114 (2019)
https://doi.org/10.1002/adma.201904114
Experimental studies to reveal the cooperative relationship between spin, energy, and polarization through intermolecular charge‐transfer dipoles to harvest nonradiative triplets into radiative singlets in exciplex light‐emitting diodes are reported. Magneto‐photoluminescence studies reveal that the triplet‐to‐singlet conversion in exciplexes involves an artificially generated spin‐orbital coupling (SOC). The photoinduced electron parametric resonance measurements indicate that the intermolecular charge‐transfer occurs with forming electric dipoles (D+•→A−•), providing the ionic polarization to generate SOC in exciplexes.
Yingying Zhang, Xiong Li, Tingting Dai, Wentao Ha, Hongyu Du, Shuai Li, Kang Wang, Fanwen Meng, Denghui Xu, and Aicong Geng
J. Phys. Chem. C 123, 24446 (2019)
Victoria Wißdorf, Markus Frericks, Michael Tzschoppe, Paula Connor, Sebastian Beck, Christof Pflumm, Annemarie Pucci, Wolfram Jaegermann, and Eric Mankel
ACS Appl. Electron. Mater. 1, 1994 (2019)
Balthasar Blülle, Stéphane Altazin, Bérengère Frouin, Lidia Stepanova, Sandra Jenatsch, Beat Ruhstaller
SID 2019 DIGEST 50, 407 (2019)
https://doi.org/10.1002/sdtp.13285
Quantum dot (QD) enhanced LCDs are among today’s best-inclass displays exhibiting high brightness and large color gamut. In this presentation we focus on the underlying key mechanism of the embedded QD films, the down-conversion of light, and explore the optical characteristics of a state-of-the-art perovskite QD film by measuring its down-converting properties as a function of the viewing angle. The good agreement of the experimental results with simulations of the QD film indicates that computer aided parameter optimization can be key tool for engineering QD displays.
Safakath Karuthedath, Yuliar Firdaus, Ru-Ze Liang, Julien Gorenflot, Pierre M. Beaujuge, Thomas D. Anthopoulos, and Frédéric Laquai
Advanced Energy Materials 9, 1901443 (2019)
Martin T. Neukom, Andreas Schiller, Simon Züfle, Evelyne Knapp, Jorge Ávila, Daniel Pérez-del-Rey, Chris Dreessen, Kassio P.S. Zanoni, Michele Sessolo, Henk J. Bolink, Beat Ruhstaller
ACS Applied Materials and Interfaces 11, 23320 (2019)
https://pubs.acs.org/doi/10.1021/acsami.9b04991
A variety of experiments on vacuum-deposited methylammonium lead iodide perovskite solar cells are presented, including JV curves with different scan rates, light intensity-dependent open-circuit voltage, impedance spectra, intensity-modulated photocurrent spectra, transient photocurrents, and transient voltage step responses. All these experimental data sets are successfully reproduced by a charge drift-diffusion simulation model incorporating mobile ions and charge traps using a single set of parameters. While previous modeling studies focused on a single experimental technique, we combine steady-state, transient, and frequency-domain simulations and measurements. Our study is an important step toward the quantitative simulation of perovskite solar cells, leading to a deeper understanding of the physical effects of these materials. The analysis of the transient current upon voltage turn-on in the dark reveals that the charge injection properties of the interfaces are triggered by the accumulation of mobile ionic defects. We show that the current rise of voltage step experiments allows for conclusions about the recombination at the interface. Whether one or two mobile ionic species are used in the model has only a minor influence on the observed effects. A delayed current rise observed upon reversing the bias from +3 to -3 V in the dark cannot be reproduced yet by our drift-diffusion model. We speculate that a reversible chemical reaction of mobile ions with the contact material may be the cause of this effect, thus requiring a future model extension. A parameter variation is performed in order to understand the performance-limiting factors of the device under investigation.
Min-Geun Song, Kwan-Soo Kim, Hye In Yang, Seong Keun Kim, Jae-Hyun Kim, Chang-Wook Han, Hyun-Chul Choi, Ramchandra Pode, Jang Hyuk Kwon
Organic Electronics 76, 105418 (2019)
Toshinori Matsushima, Fatima Bencheikh, Takeshi Komino, Matthew R. Leyden, Atula S. D. Sandanayaka, Chuanjiang Qin and Chihaya Adachi
Nature 572, 502 (2019)
https://doi.org/10.1038/s41586-019-1435-5
We show that extraordinarily thick OLEDs can be fabricated by using the organic-inorganic perovskite methylammonium lead chloride, CH3NH3PbCl3 (MAPbCl3), instead of organics as the transport layers. Because MAPbCl3 films have high carrier mobilities and are transparent to visible light, we were able to increase the total thickness of MAPbCl3 transport layers to 2,000 nanometres—more than ten times the thickness of standard OLEDs—without requiring high voltage or reducing either internal electroluminescence quantum efficiency or operational durability. These findings will contribute towards a higher production yield of high-quality OLEDs, which may be used for other organic devices, such as lasers, solar cells, memory devices, and sensors.
R. Meitzner, M.Manceau, P. Troshin, F. Brunetti, G. Polino, Ulrich S. Schubert, M.Lira-Cantu, H.Hoppe
Solar Energy Materials and Solar Cells 202, 110151 (2019)
https://doi.org/10.1016/j.solmat.2019.110151
A cooperative study conducted between different laboratories to investigate organic solar cell degradation with respect to P3HT material properties and different solar cell architectures. Some materials properties were found to be more important than others for obtaining long lifetimes and high stability of P3HT-based polymer solar cells.
Yong Cui, Yuming Wang, Jonas Bergqvist, Huifeng Yao, Ye Xu, Bowei Gao, Chenyi Yang, Shaoqing Zhang, Olle Inganäs, Feng Gao and Jianhui Hou
Nature Energy 4, 768 (2019)
Jung Hyuk Im, Kyung-Tae Kang, Jong Sun Choi and Kwan Hyun Cho
Journal of Luminescence 203, 540 (2018)
Jwo-Huei Jou, Jia-Wei Weng, Sudam Dhudaku Chavhan, Rohit Ashok Kumar Yadav, Tzu-Wei Liang
Journal of Physics D 51 (45), 454002 (2018)
Hyunsu Cho, Chul Woong Joo, Byoung-Hwa Kwon, Nam Sung Cho, Jonghee Lee
Organic Electronics 62, 72 (2018)
Hyunkoo Lee, Jonghee Lee, Jeong-Ik Lee and Nam Sung Cho
Electronics 7,155 (2018)
Dario Di Carlo Rasi, Koen H. Hendriks, Martijn M. Wienk, and René A. J. Janssen
Advanced Materials, 2018, 1803836
https://doi.org/10.1002/adma.201803836
Abstract:
A monolithic two-terminal solution-processed quadruple junction polymer solar cell in an n–i–p (inverted) configuration with four complementary polymer: fullerene active bulk-heterojunction layers is presented. The subcells possess different optical bandgaps ranging from 1.90 to 1.13 eV. Optical modeling using the transfer matrix formalism enables the prediction of the fraction of absorbed photons from sunlight in each subcell and determines the optimal combination of layer thicknesses. The quadruple junction cell features an open-circuit voltage of 2.45 V and has a power conversion efficiency of 7.6%, only slightly less than the modeled value of 8.2%. The external quantum efficiency spectrum, determined with appropriate light and voltage bias conditions, exhibits, in general, an excellent agreement with modeled spectrum. The device performance is presently limited by bimolecular recombination, which prevents using thick photoactive layers that could absorb light more efficiently.
Markus Regnat, Kurt P. Pernstich, Simon Züfle, and Beat Ruhstaller
ACS Applied Materials & Interfaces 10,31552 (2018)
https://doi.org/10.1021/acsami.8b09595
Abstract: From s-polarized, angle-dependent measurements of the electroluminescence spectra in a three-layer phosphorescent organic light-emitting diode, we calculate the exciton distribution inside the 35 nm thick emission layer. The shape of the exciton profile changes with the applied bias due to differing field dependencies of the electron and hole mobilities. A split emission zone with high exciton densities at both sides of the emission layer is obtained, which is explained by the presence of energy barriers and similar electron and hole mobilities. A peak in the transient electroluminescence signal after turn-off and the application of a reverse bias is identified as a signature of a split emission zone.
S. Jenatsch, S. Altazin, P.-A. Will, M. T. Neukom, E. Knapp, S. Züfle, S. Lenk, S. Reineke, and B. Ruhstaller
Journal of Applied Physics 124, 105501 (2018)
https://doi.org/10.1063/1.5044494
Abstract: Single-carrier devices are an excellent model system to study charge injection and charge transport properties of (doped) transport layers and to draw conclusions about organic electronics devices in which they are used. By combining steady-state and impedance measurements at varying temperatures of hole-only devices with different intrinsic layer thicknesses, we are able to determine all relevant material parameters, such as the charge mobility and the injection barrier. Furthermore, the correlation and sensitivity analyses reveal that the proposed approach to study these devices is especially well suited to extract the effective doping density, a parameter that cannot be easily determined otherwise. The effective doping density is crucial in organic light-emitting diodes (OLEDs) for realizing efficient injection, charge balance, and lateral conductivity in display or lighting applications. With the fitted drift-diffusion device model, we are further able to explain the extraordinary two-plateau capacitance–frequency curve of these hole-only devices, which originates from charges that flow into the intrinsic layer at zero applied offset voltage. We demonstrate that the observation of this behavior is a direct indication for ideal charge injection properties and the observed capacitance–frequency feature is linked to the charge carrier mobility in the intrinsic layer. The extracted material parameters may directly be used to simulate and optimize full OLED devices employing the investigated hole-injection and -transport materials.
Stéphane Altazin, Lieven Penninck, and Beat Ruhstaller
Handbook of Organic Light-Emitting Diodes, Springer Nature 2018
Jin Xu, Andreas Sandström, Erik Mattias Lindh, Wei Yang, Shi Tang, and Ludvig Edman
ACS Appl. Mater. Interf., 2018. 10 , 33380
Akanksha Jetly and Rajesh Mehra
International Journal of Optics
Volume 2018, Article ID 9458530
Kyungnam Kang, Kyoung-Youm Kim, and Jungho Kim
Optics Express 26, A955 (2018)
Sheng Bi, Zhongliang Ouyang, Shoieb Shaik and Dawen Li
Scientific Reports 8, 9574 (2018)
S. Altazin, C. Kirsch, E. Knapp, A. Stous, and B. Ruhstaller
Journal of Applied Physics 124, 135501 (2018)
https://doi.org/10.1063/1.5043245
Abstract: We present a new approach to simulate the transport of charges across organic/organic layer interfaces in organic semiconductor devices. This approach combines the drift-diffusion formalism away from the interface with a hopping description of the charge transport in the vicinity of the interface. It has been implemented in the commercial software SETFOS allowing for fast simulations of the complete device. This new model takes into account both recombination and generation mechanisms across the interface enabling the modeling of charge-generation/recombination interfaces for the numerical simulation of tandem devices. Using this approach, it is also possible to simulate devices using 1,4,5,8,9,11-Hexaazatriphenylenehexacarbonitrile as a hole-injection layer. This particular material has a very deep HOMO level (approximately 9.5 eV), which would seemingly prevent such a layer to be used as a hole-injection material in the framework of traditional drift-diffusion models.
Michele De Bastiani, Erkan Aydin, Thomas Allen, Daniel Walter, Andreas Fell, Jun Peng, Nicola Gasparini, Joel Troughton, Derya Baran, Klaus Weber, Thomas P. White, and Stefaan De Wolf
Advanced Electronic Materials 2018, 1800500
https://doi.org/10.1002/aelm.201800500
Abstract: Charge accumulation at the electron and hole transport layers generates anomalous electrical behavior in perovskite solar cells (PSCs). Hysteresis in the current voltage characteristic and recombination at the interfaces are the clearest manifestations of this phenomenon, which compromises device performance and stability. Here, the underlying charge-carrier dynamics of a variety of PSCs are investigated by analyzing their transient photocurrent response. Towards shorter time scales, PSCs often show increasingly severe hysteretic responses. This phenomenon is correlated with the presence of interfacial accumulated charges that hinders the photogenerated carrier extraction process. However, introducing passivating contacts improves the carrier-injection properties and the devices become completely hysteresis free. These results underline the importance of contact passivation for PSCs and the need to further develop new passivating interlayers that simultaneously eliminate charge-carrier recombination and provide selective transport for each carrier type at the PSC’s contacts.
Yuan Xiong, Long Ye, Abay Gadisa, Qianqian Zhang, Jeromy James Rech, Wei You, and Harald Ade
Advanced Functional Materials 2018, 1806262
Taesoo Kim, Yuliar Firdaus, Ahmad R. Kirmani, Ru-Ze Liang, Hanlin Hu, Mengxia Liu, Abdulrahman El Labban, Sjoerd Hoogland, Pierre M. Beaujuge, Edward H. Sargent, and Aram Amassian
ACS Energy Letters 3, 1307 (2018)
Indunil Angunawela, Long Ye, Haijun Bin, Zhi-Guo Zhang, Abay Gadisa, Yongfang Li and Harald Ade
Materials Chemistry Frontiers, 2018
Alejandro N. Filippin, Tzu-Ying Lin, Michael Rawlence, Tanja Zünd, Kostiantyn Kravchyk, Jordi Sastre-Pellicer, Stefan G. Haass, Aneliia Wäckerlin, Maksym V. Kovalenkoab and Stephan Buecheler
RSC Adv., 2018, 8, 20304
https://doi.org/10.1039/C8RA02461H
Abstract:
To obtain full advantage of state-of-the-art solid-state lithium-based batteries, produced by sequential deposition of high voltage cathodes and promising oxide-based electrolytes, the current collector must withstand high temperatures (>600 °C) in oxygen atmosphere. This imposes severe restrictions on the choice of materials for the first layer, usually the cathode current collector. It not only must be electrochemically stable at high voltage but also remain conductive upon deposition and annealing of the subsequent layers without presenting a strong diffusion of its constituent elements into the cathode. A novel cathode current collector based on a Ni-Al–Cr superalloy with target composition Ni0.72Al0.18Cr0.10 is presented here. The suitability of this superalloy as a high voltage current collector was verified by determining its electrochemical stability at high voltage by crystallizing and cycling LiCoO2 directly onto it.
Martin Neukom, Simon Züfle, Sandra Jenatsch, Beat Ruhstaller
Science Tech. Adv. Mater., 2018, 19, 291
Download Supplemental Information (PDF)
https://doi.org/10.1080/14686996.2018.1442091
Abstract: We present an overview of opto-electronic characterization techniques for solar cells including light-induced charge extraction by linearly increasing voltage, impedance spectroscopy, transient photovoltage, charge extraction and more. Guidelines for the interpretation of experimental results are derived based on charge drift-diffusion simulations of solar cells with common performance limitations. It is investigated how nonidealities like charge injection barriers, traps, and low mobilities among others manifest themselves in each of the studied cell characterization techniques. Moreover, comprehensive parameter extraction for an organic bulk-heterojunction solar cell comprising PCDTBT:PC70BM is demonstrated. The simulations reproduce the measured results of 9 different experimental techniques. Parameter correlation is minimized due to the combination of various techniques. Thereby a route to comprehensive and accurate parameter extraction is identified.
Tzu-Hung Yeh, Chih-Chien Lee, Chun-Jen Shih, Gautham Kumar, Sajal Biring, Shun-Wei Liu
Organic Electronics 59, 266 (2018)
S. Altazin, L. Stepanova, J. Werner, B. Niesen, C. Ballif, and B. Ruhstaller
Optics Express 26, A579 (2018)
https://doi.org/10.1364/OE.26.00A579
Abstract:We present an optical model implemented in the commercial software SETFOS 4.6 for simulating perovskite/silicon monolithic tandem solar cells that exploit light scattering structures. In a first step we validate the model with experimental data of tandem solar cells that either use front- or rear-side textures and extract the internal quantum efficiency of the methyl-ammonium lead iodide (MALI) perovskite sub-cell. In a next step, the software is used to investigate the potential of different device architectures featuring a monolithic integration between the perovskite and silicon sub-cells and exploiting rear- as well as front-side textures for improved light harvesting. We find that, considering the available contact materials, the p-i-n solar cell architecture is the most promising with respect to achievable photocurrent for both flat and textured wafers. Finally, cesium-formamidinium-based perovskite materials with several bandgaps were synthetized, optically characterized and their potential in a tandem device was quantified by simulations. For the simulated layer stack and among the tested materials with bandgaps of 1.7 and 1.6 eV, the one with 1.6 eV bandgap was found to be the most promising, with a potential of reaching a power conversion efficiency of 31%. In order to achieve higher efficiencies using higher band-gap materials, parasitic absorptance in the blue spectral range should be further reduced.
Dario Di Carlo Rasi, Koen H. Hendriks, Gaël H. L. Heintges, Giulio Simone, Gerwin H. Gelinck, Veronique S. Gevaerts, Ronn Andriessen, Geert Pirotte,Wouter Maes, Weiwei Li, Martijn M. Wienk, and René A. J. Janssen
Sol. RRL, 2018, 2, 1800018
https://onlinelibrary.wiley.com/doi/pdf/10.1002/solr.201800018
Andrius Devižis, Sandra Jenatsch, Matthias Diethelm, Vidmantas Gulbinas, Frank Nüesch, Roland Hany
ACS Photonics, 2018, 5 (8), pp 3124-3131
Karen Strassel, Adrian Kaiser, Sandra Jenatsch, Anna C. Véron, Surendra B. Anantharaman, Erwin Hack, Matthias Diethelm, Frank Nüesch, Rian Aderne, Cristiano Legnani, Sergii Yakunin, Marco Cremona, and Roland Hany
ACS Appl. Mater. Interf., 2018, 10, 11063
Amin Salehi, Ying Chen, Xiangyu Fu, Cheng Peng, and Franky So
ACS Appl. Mater. Interf., 2018, 10, 9595
Lei Wang, Sandra Jenatsch, Beat Ruhstaller, Christian Hinderling, Donatas Gesevicius, Roland Hany, and Frank Nüesch
Advanced Functional Materials 28,1705724 (2018)
Matthias Diethelm, Lieven Penninck, Stéphane Altazin, Roman Hiestand, Christoph Kirsch & Beat Ruhstaller
Journal of Information Display, 2018, 19, 61
https://doi.org/10.1080/15980316.2018.1428232
Abstract:The resolution of organic light-emitting diode (OLED) displays is increasing steadily as these displays are adopted for mobile and virtual reality (VR) devices. This leads to a stronger pixel crosstalk effect, where the neighbors of active pixels unintentionally emit light due to a lateral electric current between the pixels. Recently, the crosstalk was quantified by measuring the current flowing through the common hole transport layer between the neighboring pixels and comparing it to the current through the active pixel diode [S.-K. Kwon, K.-S. Kim, H.-C. Choi and J. H. Kwon, presented at the International Meeting on Information Display, Jeju, South Korea, 2016]. The measurements showed that the crosstalk is more crucial for low light levels. In such cases, the intended and parasitic currents are similar. The simulations performed in this study validated these measurement results. By simulations, we quantify the crosstalk current through the diode. The luminous intensity can be calculated with the measured current efficiency of the diodes. For low light levels, the unintended luminance can reach up to 40% of the intended luminance. The luminance due to pixel crosstalk is perceivable by humans. This effect should be considered for OLED displays with resolutions higher than 300 PPI.
Dae-Hyeon Kim, Anthony D’Aléo, Xian-Kai Chen, Atula D. S. Sandanayaka, Dandan Yao, Li Zhao, Takeshi Komino, Elena Zaborova, Gabriel Canard, Youichi Tsuchiya, Eunyoung Choi, Jeong Weon Wu, Frédéric Fages, Jean-Luc Brédas, Jean-Charles Ribierre and Chihaya Adachi
Nature Photonics, Vol. 12, February 2018. p. 98–104
Sandra Jenatsch, Markus Regnat, Roland Hany, Matthias Diethelm, Frank Alain Nüesch, and Beat Ruhstaller
ACS Photonics 5, 1591 (2018)
https://pubs.acs.org/doi/abs/10.1021/acsphotonics.8b00047
Abstract:Light-emitting electrochemical cells (LECs) are one of the simplest electroluminescent devices and consist of a single emissive organic/salt layer sandwiched between two electrodes. The unique attribute of an operated LEC is the development of a pdoped/ intrinsic/n-doped (p-i-n) structure in the active layer in which the doped regions allow for facile transport of electronic charges to the intrinsic region, where charge recombination and light emission occur. However, due to the complex and simultaneous motion of ionic and electronic charges, the examination of the p-i- n structure and the zone where the light is emitted (EZ) is challenging during operation. By analyzing incident photon-tocurrent conversion efficiency and angular emission measurements with optical simulations, and correlating the results with capacitance measurements, we are able to obtain a clear picture of the p-i-n situation and the EZ within the active layer of a sandwich-type LEC during operation. It is found that the p-doped zone grows to the center of the active layer while the EZ stays closer to the metal electrode and is unchanged over time. Furthermore, optical simulations reveal that the determined EZ limits the external quantum efficiency of the LEC by outcoupling efficiencies of less than 10%.
Bei Yang, Yu Chen, Yong Cui, Delong Liu, Bowei Xu and Jianhui Hou
Adv. Energy Mater. 2018, 8, 1800698
Jwo-Huei Jou, Tzu-Chieh Tai, Yu-Ting Su, Hui-Huan Yu, Chi-Heng Chiang, Sudam D. Chavhan, You-Ting Lin, Jing-Jong Shyue, and Tzu-Wei Liang
Physica status solidi A, 2018
Francesco Pagani, Evelyn Stilp, Reto Pfenninger, Eduardo Cuervo Reyes, Arndt Remhof, Zoltan Balogh-Michels, Antonia Neels, Jordi Sastre-Pellicer, Michael Stiefel, Max Döbeli, Marta D Rossell, Rolf Erni, Jennifer L.M. Rupp, and Corsin Battaglia
ACS Appl. Mater. Interfaces, 2018
https://doi.org/10.1021/acsami.8b16519
Abstract:
Using an epitaxial thin-film model system deposited by pulsed laser deposition (PLD), we study the Li-ion conductivity in Li4Ti5O12, a common anode material for Li-ion batteries. Epitaxy, phase purity, and film composition across the film thickness are verified employing out-of-plane and in-plane X-ray diffraction, transmission electron microscopy, time-of-flight mass spectrometry, and elastic recoil detection analysis. We find that epitaxial Li4Ti5O12 behaves like an ideal ionic conductor that is well described by a parallel RC equivalent circuit, with an ionic conductivity of 2.5 × 10–5 S/cm at 230 °C and activation energy of 0.79 eV in the measured temperature range of 205 to 350 °C. Differently, in a co-deposited polycrystalline Li4Ti5O12 thin film with an average in-plane grain size of <10 nm, a more complex behavior with contributions from two distinct processes is observed. Ultimately, epitaxial Li4Ti5O12 thin films can be grown by PLD and reveal suitable transport properties for further implementation as zero-strain and grain boundary-free anodes in future solid-state microbattery designs.
Yingying Zhang, Xiong Li, Denghui Xu, Fanwen Meng, Rong Hu, Jia Zhao
Surface & Coatings Technology, 2018
Yi-Ting Lee, Po-Chen Tseng, Takeshi Komino, Masashi Mamada, Ruby Janet Ortiz, Man-Kit Leung, Tien-Lung Chiu, Chi-Feng Lin, Jiun-Haw Lee, Chihaya Adachi, Chao-Tsen Chen, and Chin-Ti Chen
ACS Appl. Mater. Interfaces, 2018
Ru-Ze Liang, Maxime Babics, Victoria Savikhin, Weimin Zhang, Vincent M. Le Corre, Sergei Lopatin, Zhipeng Kan, Yuliar Firdaus, Shengjian Liu, Iain McCulloch, Michael F. Toney, and Pierre M. Beaujuge
Adv. Energy Mater. 2018, 8, 1800264
Matthias Diethelm, Quirin Grossmann, Andreas Schiller, Evelyne Knapp, Sandra Jenatsch, Maciej Kawecki, Frank Nüesch, and Roland Hany
Adv. Optical Mater. 2018, 1801278
https://doi.org/10.1002/adom.201801278
Abstract: Effects of ion concentration and active layer thickness play a critical role in the performance of light-emitting electrochemical cells. Expanding on a pioneering materials system comprising the super yellow (SY) polymer and the electrolyte trimethylolpropane ethoxylate (TMPE)/Li+CF3SO3 -, it is reported that a slightly lowered salt concentration and layer thickness result in a substantial efficiency increase and that this increase is confined to a narrow concentration and thickness range. For a film thickness of 70 nm, a blend ratio SY:TMPE:Li+CF3SO3 - = 1:0.075:0.0225, and a current of 7.7 mA cm-2 the current efficacy is 11.6 cd A-1, on a par with SY light-emitting diodes. The optimized salt content can be explained by increased exciton quenching at higher concentrations and hindered carrier injection and conduction at lower concentrations, while the optical dependence on the layer thickness is due to weak microcavity effects. A comprehensive optical modeling study is presented, which includes the doping-induced changes of the refractive indices and self-absorption losses due to the emission–absorption overlap of intrinsic and doped SY. The analysis indicates either a thickness-independent emitter position (EP) close to the anode or a thickness-dependent EP, shifted to the cathode for increased thicknesses.
![Isomeric spiro-[acridine-9,90-fluorene]-2,6- dipyridylpyrimidine based TADF emitters: insights into photophysical behaviors and OLED performances](https://images.squarespace-cdn.com/content/v1/56373af5e4b030f21bd0dc1a/1619444221844-K62EWZM9XOWDT0AAOVGN/Isomeric+spiro-acridine-9%2C90-fluorene-2%2C6-+dipyridylpyrimidine+based+TADF+emitters+insights+into+photophysical+behaviors+and+OLED+performances.png)
Paramaguru Ganesan, Deng-Gao Chen, Jia-Ling Liao, Wei-Cheng Li, Yi-Ning Lai, Dian Luo, Chih-Hao Chang, Chang-Lun Ko, Wen-Yi Hung, Shun-Wei Liu, Gene-Hsiang Lee, Pi-Tai Chou and Yun Chi
J. Mater Chem. C, 2018, 6, 10088-10100
Toshinori Matsushima, Chuanjiang Qin, Kenichi Goushi, Fatima Bencheikh, Takeshi Komino, Matthew Leyden, Atula S. D. Sandanayaka, and Chihaya Adachi
Adv. Mater. 2018, 1802662
https://doi.org/10.1002/adma.201802662
Abstract: The development of host materials with high performance is essential for the fabrication of efficient and stable organic light-emitting diodes (OLEDs). Although host materials used in OLEDs are typically organics, in this study, it is shown that the organic-inorganic perovskite CH3NH3PbCl3 (MAPbCl3) can be used as a host layer for OLEDs. Vacuum-evaporated MAPbCl3 films have a wide bandgap of about 3 eV and very high and relatively balanced hole and electron mobilities, which are suitable for the host material. Photoluminescence and electroluminescence take place through energy transfer from MAPbCl3 to an organic emitter in films. The incorporation of a MAPbCl3 host layer into OLEDs leads to a reduction of driving voltage and enhancement of external quantum efficiency as compared to devices with a conventional organic host layer. Additionally, OLEDs with a MAPbCl3 host layer demonstrate very good operational stability under continuous current operation. These results can be extensively applied to organic- and perovskite-based optoelectronics.
Lieven Penninck, Matthias Diethelm, Stéphane Altazin, Roman Hiestand, Christoph Kirsch, Beat Ruhstaller
Journal of the SID 26, 546 (2018)
Shu-Wei Li, Cheng-Hung Yu, Chang-Lun Ko, Tanmay Chatterjee, Wen-Yi Hung and Ken-Tsung Wong
ACS Appl. Mater. Interfaces 2018, 10, 12930−12936
Shuai-Shuai Meng, Yan-Qing Li and Jian-Xin Tang
Organic Electronics 61, 351 (2018)
Laura Ciammaruchi et al.
Journal of Materials Research 33 (13), pp. 1909-1924 (2018)
Elisabeth Bodenstein, Matthias Schober, Marie Hoffmann, Christoph Metzner, Uwe Vogel
Journal of the SID, 2018 , 26, 555
T. Komino, Y. Sagara, H. Tanaka, Y. Oki, N. Nakamura, H.Fujimoto, and C. Adachi
Applied Physics Letters 108, 241106 (2016)
N. A. Cooling, E. F. Barnes, F. Almyahi, K. Feron, M. Al-Mudhaffer, A. Al-Ahmad, B. Vaughan , T. R. Andersen , M. J. Griffith , A. S. Hart , A. G. Lyons , W. J. Belcher , P. C. Dastoor
J. Mater. Chem. A 4, 10274 (2016)
T. Lanz, K. Lapagna, S. Altazin, M. Boccard, F.J. Haug, C. Ballif, B. Ruhstaller
Optics Express 23 (11), A539-A546, (2015)
https://doi.org/10.1364/OE.23.00A539
T. R. Andersen, F. Almyahi, N. A. Cooling, D. Elkington, L. Wiggins, A. Fahya, K. Feron, B. Vaughan, M. J. Griffith, A. J. Mozer, C. Saekung, G. G. Wallace, W. J. Belcher, and P. C. Dastoor.
Journal of Materials Chemistry A 4, 15986 (2016)
DOI: 10.1039/x0xx00000x
Rohit Ashok Kumar Yadav, Deepak Kumar Dubey, Sun-Zen Chen, Sujith Sudheendran Swayamprabha, Tzu-Wei Liang, Jwo-Huei Jou
MRS Advances, 2018, 3, 3445
Alessia Senes, Stefan C. J. Meskers, Wijnand M. Dijkstra, Jacobus J. van Franeker, Stéphane Altazin, Joanne S. Wilson and René A. J. Janssen
J. Mater. Chem. C, 2016, 4, 6302
Konrad Domanski, Essa A. Alharbi, Anders Hagfeldt, Michael Grätzel and Wolfgang Tress
Nature Energy 3, 61 (2018)
https://www.nature.com/articles/s41560-017-0060-5
Description:
The authors investigate the effects of different environmental factors and electrical load on the ageing behaviour of perovskite solar cells. They also demonstrate how the results of the experiments can be distorted and how to avoid the common pitfalls.
Xin Song, Nicola Gasparini, and Derya Baran
Advanced Electronic Materials 4,1700358 (2018)
Nobuhiro Nakamura, Junghwan Kim, Koji Yamamoto, Satoru Watanabe, and Hideo Hosono
Organic Electronics 51, 103 (2017)
Mohammed F. Al-Mudhaffera, Matthew J. Griffith, Krishna Feron, Nicolas C. Nicolaidis, Nathan A. Cooling, Xiaojing Zhou, John Holdsworth, Warwick J. Belcher, Paul C. Dastoor
Solar Energy Materials and Solar Cells 175, 77 (2018)
Kai-Ming Chiang, Bo-Wei Hsu, Yi-An Chang, Lin Yang, Wei-Lun Tsai, and Hao-Wu Lin
ACS Applied Materials & Interfaces 9, 40516 (2017)
https://doi.org/10.1021/acsami.7b12805
Abstract:In this work, a sequential vacuum deposition process of bright, highly crystalline, and smooth methylammonium lead bromide and phenethylammonium lead bromide perovskite thin films are investigated and the first vacuum-deposited organometallic halide perovskite light-emitting devices (PeLEDs) are demonstrated. Exceptionally low refractive indices and extinction coefficients in the emission wavelength range are obtained for these films, which contributed to a high light out-coupling efficiency of the PeLEDs. By utilizing these perovskite thin films as emission layers, the vacuum-deposited PeLEDs exhibit a very narrow saturated green electroluminescence at 531 nm, with a spectral full width at half-maximum bandwidth of 18.6 nm, a promising brightness of up to 6200 cd/m2, a current efficiency of 1.3 cd/A, and an external quantum efficiency of 0.36%.
ung-Yu Li, Shih-Pu Chen, Huei-Jhen Siao, Jin-Han Wu, Guan-Yu Chen, Cheng-Chang Chen, Shu-Yi Ho, Yi-Ping Lin, Hong-Hui Hsu, Jin-Sheng Lin, Ming-Shan Jeng, Nai-Chuan Chen, Hui-Kai Zeng, and Jenh-Yih Juang
Appl. Phys. Lett. 111, 093301 (2017)
Yea-Fen Jang, Tzu-Chun Lin, Jhih-Yan Guo, Chien-Ming Fan Chiang, Ming-Lun Wu, Hsin-Yi Shen, Tsung-Cheng Chen, Zu-Po Yang, Ya-Ju Lee, Hai-Ching Su, Chih-Hao Chang, Shun-Wei Liu
Organic Electronics, 2017, 51, 129
Long Ye, Yuan Xiong, Sunsun Li, Masoud Ghasemi, Nrup Balar, Johnathan Turner, Abay Gadisa, Jianhui Hou, Brendan T. O’Connor, and Harald Ade
Advanced Functional Materials 27,1702016 (2017)
Takeshi Gotanda, Shigehiko Mori, Haruhi Oooka, Hyangmi Jung, Hideyuki Nakao, Kenji Todori, and Yutaka Nakai
Journal of Materials Research 32,2700 (2017)
Abstract:
Perovskite solar cells are promising for realizing high power conversion efficiency (PCE) with low manufacturing costs, but efficient coating methods are needed for commercialization. Here, a gas blowing method was used to fabricate perovskite solar cells and was found to create a smooth perovskite layer and to prevent voids in large-area cells, when organic materials were used as scaffolds for forming the perovskite. A PCE of 13% in a 1 cm2 active area is achieved by tuning the band-gap energy of MAPbX3 via substitution of Br for I ions in X sites. Incorporation of a poly(3,4-ethylenedioxythiophene) hole transport layer with a higher work function increased the open circuit voltage of the solar cells. All layers of the cells were fabricated at low temperatures (,140 °C), which makes it possible to incorporate a polymer substrate for producing flexible solar cells and high-throughput fabrication.
C Kirsch, S Altazin, R Hiestand, T Beierlein, R Ferrini, T Offermans, L Penninck, B Ruhstaller
S. Olivier, E. Ishow, S. Meunier Della-Gatta, T. Maindron
Organic Electronics 49, 24 (2017)
S. Jenatsch, L. Wang, N. Leclaire, E. Hack, R. Steim, S.B. Anantharaman, J. Heier, B. Ruhstaller, L. Penninck, F. Nüesch, R. Hany
Organic Electronics 48, 77 (2017),
Marco Natali, Santiago D. Quiroga, Luca Passoni, Luigino Criante, Emilia Benvenuti, Gabriele Bolognini, Laura Favaretto, Manuela Melucci, Michele Muccini, Francesco Scotognella, Fabio Di Fonzo, and Stefano Toffanin
Adv. Funct. Mater. 2017, 1605164
Amin Salehi, Szuheng Ho, Ying Chen, Cheng Peng, Hartmut Yersin, and Franky So
Adv. Optical Mater. 2017, 1700197
Chul Woong Joo, Keunsoo Lee, Jonghee Lee, Hyunsu Cho, Jin-Wook Shin, Nam Sung Cho, Jaehyun Moon
Journal of Luminescence 187 (2017) 433–440
https://dx.doi.org/10.1016/j.jlumin.2017.03.057
T. Lanz, E. M. Lindha and L. Edmana
Journal of Materials Chemistry C 5, 4706 (2017)
DOI: 10.1039/C7TC01022B
Martin Thomas Neukom, Simon Züfle, Evelyne Knapp, Mohammed Makha, Roland Hany, Beat Ruhstaller
Solar Energy Materials and Solar Cells 169 (2017) 159–166
https://doi.org/10.1016/j.solmat.2017.05.021
Abstract:There is increasing evidence that the presence of mobile ions in perovskite solar cells can cause a current-voltage curve hysteresis. However, it is still the subject of ongoing debates on how exactly mobile ions influence the device operation. We use drift-diffusion simulations incorporating mobile ions to describe IV curves of preconditioned methylammonium lead iodide perovskite solar cells and compare them with experimental results. Our simulation results show that the hysteresis depends on the extent of surface recombination and on the diffusion length of charge carriers. We provide a detailed explanation for the reduced hysteresis of perovskite solar cells with high power conversion efficiencies. We find that in high-efficiency solar cells ion migration is still present, but does not cause a hysteresis effect. In these devices, charge extraction is mainly driven by the diffusion of free electrons and holes.
Jan A. Mayer, Benjamin Gallinet, Ton Offermans, Igor Zhurminsky, Rolando Ferrini
Solar Energy Materials & Solar Cells 163 (2017) 51–57
D. H. Kim, K. Inada, L. Zhao, T. Komino, N. Matsumoto, J. C. Ribierre, and C. Adachi
J. Mater. Chem. C 5,1216 (2017)
Monica Morales-Masis, Stefaan De Wolf, Rachel Woods-Robinson, Joel W. Ager, and Christophe Ballif
Adv. Electron. Mater. 2017, 1600529
Simon Züfle, Stéphane Altazin, Alexander Hofmann, Lars Jäger, Martin T. Neukom, Tobias D. Schmidt, Wolfgang Brütting, Beat Ruhstaller,
J. Appl. Phys. 121, 175501, 2017.
https://doi.org/10.1063/1.4982903
Abstract:We demonstrate the application of the CELIV (charge carrier extraction by linearly increasing voltage) technique to bilayer organic light-emitting devices (OLEDs) in order to selectively determine the hole mobility in N,N0-bis(1-naphthyl)-N,N0-diphenyl-1,10-biphenyl-4,40-diamine (a-NPD). In the CELIV technique, mobile charges in the active layer are extracted by applying a negative voltage ramp, leading to a peak superimposed to the measured displacement current whose temporal position is related to the charge carrier mobility. In fully operating devices, however, bipolar carrier transport and recombination complicate the analysis of CELIV transients as well as the assignment of the extracted mobility value to one charge carrier species. This has motivated a new approach of fabricating dedicated metal-insulator-semiconductor (MIS) devices, where the extraction current contains signatures of only one charge carrier type. In this work, we show that the MIS-CELIV concept can be employed in bilayer polar OLEDs as well, which are easy to fabricate using most common electron transport layers (ETLs), like Tris-(8-hydroxyquinoline)aluminum (Alq3). Due to the macroscopic polarization of the ETL, holes are already injected into the hole transport layer below the built-in voltage and accumulate at the internal interface with the ETL. This way, by a standard CELIV experiment only holes will be extracted, allowing us to determine their mobility. The approach can be established as a powerful way of selectively measuring charge mobilities in new materials in a standard device configuration.
S. Züfle, S. Altazin, A. Hofmann, L. Jäger, M. T. Neukom, W. Brütting, and B. Ruhstaller
J. Appl. Phys. 122, 115502, 2017.
https://dx.doi.org/10.1063/1.4992041
Abstract: Charge carrier transport in organic semiconductor devices is thermally activated with characteristic activation energies in the range of 0.2–0.6 eV, leading to strongly temperature-dependent behavior. For designing efficient organic semiconductor materials and devices, it is, therefore, indispensable to understand the origin of these activation energies. We propose that in bilayer organic light-emitting diodes (OLEDs) employing a polar electron transport layer, as well as in metal-insulator-semiconductor (MIS) devices, the hole injection barrier Einj and the hole mobility activation energy El can be decoupled from each other if temperature-dependent capacitance frequency (C-f-T) and MIS-CELIV (charge extraction by linearly increasing voltage) experiments are combined. While the C-f-T signal contains information of both injection and transport, the CELIV current is expected to be insensitive to the electrode injection properties. We employ numerical drift-diffusion simulations to investigate the accuracy of this analytical parameter extraction approach and to develop criteria for its validity. We show that the implicit assumption of constant charge density and field profiles leads to systematic errors in determining the activation energies. Thus, one should be aware of the intrinsic limitations of the analytical Arrhenius fit, and for more accurate parameter determination full drift-diffusion modeling is advised. Applying the analytical method to a standard bilayer OLED, we find that the total activation energy of 0.5 eV for the hole current can be split into contributions of 0.25 eV each for injection barrier and mobility. Finally, we also discuss the broader applicability of this method for other device stacks and material combinations.
L. Zhao, T. Komino, D. Hyeon Kim, M. Hasnan Sazzad, D. Pitrat, J.-C. Mulatier, C. Andraud, J.-C. Ribierre and C. AdachiJ. Mater. Chem. C, 2016, 4, 11557
H. Zhang, B. Niesen, E. Hack, S. Jenatsch, L. Wang, A. C. Veron, M. Makha, R. Schneider, Y. Arroyo, R. Hany, F. Nüesch
Organic Electronics 30 (2016) 191-199
http://dx.doi.org/10.1016/j.orgel.2015.12.013
J. Mayer, B. Gallinet, T. Offermans and R. Ferrini
Optics Express 24, A358 (2016)
Doi:10.1364/oe.24.00a358
S. Altazin, S. Züfle, E. Knapp, C. Kirsch, T.D. Schmidt, L. Jäger, W. Brütting, B. Ruhstaller
SID Digest of Technical Papers 47, 1750 (2016)
https://doi.org/10.1002/sdtp.11059
Shiho Oyama, Heisuke Sakai, and Hideyuki Murata
Japanese Journal of Applied Physics 55, 03DD13 (2016)
http://doi.org/10.7567/JJAP.55.03DD13
M. L. Inche Ibrahim
Journal Of Applied Physics 119, 154504 (2016)
Sandra Jenatsch, Lei Wang, Matia Bulloni, Anna Christina Véron, Beat Ruhstaller, Stéphane Altazin, Frank Alain Nüesch, and Roland Hany
ACS Appl. Mater. Interfaces 8, 6554 (2016)
S. Altazin, L. Stepanova, K. Lapagna, P. Losio, J. Werner, B. Niesen, A. Dabirian, M. Morales-Masis, S. de Wolf, C. Ballif, B. Ruhstaller
32nd European Photovoltaic Solar Energy Conference and Exhibition, pp 1276 - 1279 , 2016
https://doi.org/10.4229/EUPVSEC20162016-3DV.2.2
S. Altazin, S. Züfle, E. Knapp, C. Kirsch, T.D. Schmidt, L. Jäger, Y. Noguchi, W. Brütting, B. Ruhstaller
Organic Electronics 39 (2016) 244-249
Hyunsu Cho, Chul Woong Joo, Jonghee Lee, Hyunkoo Lee,Jaehyun Moon, Jeong-IK Lee, Jun Yeob Lee, Youngjin Kang andNam Sung Cho
Optics Express 24, 24161 (2016)
https://dx.doi.org/10.1364/OE.24.024161
Martin Neukom,
Msc Thesis, Jan 2016.arXiv:1611.06425 [cond-mat.mtrl-sci]download PDF
Abstract:Transient opto-electrical measurements of methylammonium lead iodide (MALI) perovskite solar cells (PSCs) are performed and analyzed in order to elucidate the operating mechanisms. The current response to a light pulse or voltage pulse shows an extraordinarily broad dynamic range covering 9 orders of magnitude in time – from microseconds to minutes – until steady-state is reached. Evidence of a slowly changing charge density at the perovskite layer boundaries is found, which is most probably caused by mobile ions.
Currentvoltage curves (IV curves) are measured with very fast scan-rate after keeping the cell for several seconds at a constant voltage as proposed by Tress et al. Numerical drift-diffusion simulations reproduce the measured IV curves using different distributions of ions in the model. Analysing the band diagram of the simulation result sheds light on the operating mechanism.
To further investigate the effects at short time scales (below milliseconds) photo-generated charge extraction by linearly increasing voltage (photo-CELIV) experiments are performed. We postulate that mobility imbalance in combination with deep hole trapping leads to dynamic doping causing effects from microseconds to milliseconds. Comprehensive transient drift-diffusion simulations of the photo-CELIV experiments strengthen this hypothesis.
This advanced characterization approach combining dynamic response measurements and numerical simulations represents a key step on the way to a comprehensive understanding of device working mechanisms in emerging perovskite solar cells.
Serkan Esiner, Gijs W. P. van Pruissen, Martijn M. Wienk and René A. J. Janssen
J. Mater. Chem. A, 2016,4, 5107-5114
S. Jenatsch, R. Hany, A.C. Véron, M. Neukom, S. Züfle, A. Borgschulte, B. Ruhstaller, F. Nüesch
J. Phys. Chem. C, 118 (30), 17036, 2014
M. Eck, C.V. Phama, S. Züfle, M. Neukom, M. Seßler, D. Scheunemann, E. Erdem, S. Weber, H. Borchert, B. Ruhstaller, M. Krüger
Physical Chemistry Chemical Physics, 16 (24) 12251, 2014
S. Zhang, Z. Liu, X. Wang, S. Yue, Z. Zhang, Q. Wu, G. Xie, Q. Xue, Y. Chen, P. Wang, R. Gu, D. Qu, Y. Zhao, S. Liu
Thin Solid Films 537, 221 (2013)
J. Singh, M. Narayan
Nanoscience and Technology, 1(1), 8, 2013.
B. Perucco, N.A. Reinke, D. Rezzonico, E. Knapp, S. Harkema, B. Ruhstaller
Organic Electronics 13, 1827 (2012)
https://doi.org/10.1016/j.orgel.2012.05.053
S. Zhang, G. Xie, Q. Xue, Z. Zhang, L. Zhao, Y. Luo, S. Yue, Y. Zhao, S. Liu
Thin Solid Films 520, 2966 (2012)
M.T. Neukom, S. Züfle, B. Ruhstaller
Organic Electronics 13, 2910 (2012)
E. Knapp, B. Ruhstaller
Journal of Applied Physics 112,024519 (2012)
V.S. Gevaerts, J.A. Koster, M.M. Wienk, R.A. Janssen
ACS Applied Materials & Interfaces 3, 9, 3252 (2011)
U. Hörmann, J. Wagner, M. Gruber, A. Opitz, W. Brütting
Physica Status Solidi Rapid Research Letters, 5, 241 (2011)
E. Knapp, B. Ruhstaller
Optical and Quantum Electronics, 42,667 (2011)
B. Ruhstaller, E. Knapp, B. Perucco, N. Reinke, D. Rezzonico and F. Müller
Optoelectronic Devices and Properties, Oleg Sergiyenko (Ed.)
ISBN 978-953-307-204-3, 2011
M. Neukom, N.A. Reinke, B. Ruhstaller
Solar Energy 85, 1250 (2011)
J. Hauss, T. Bocksrocker, B. Riedel, U. Lemmer, M. Gerken,
Optics Express 19, a851 (2011)
D. Rezzonico, B. Perucco, E. Knapp, R. Häusermann, N.A. Reinke, F. Müller, B. Ruhstaller
Journal of Photonics for Energy, 1, 011005-1-11, 2011.
https://doi.org/10.1117/1.3528045
Yueh-Tsung Tsai, Kensuke Goto, Osamu Yoshikawa, Shogo Mori, Takashi Sagawa and Susumu Yoshikawa
Japanese Journal of Applied Physics 50 (2011) 01BC13
Mark L. Hildner, Jonathan M. Ziebarth
SID Digest of Technical Papers 42,1764 (2011)
