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Sami Toikkonen, G. Krishnamurthy Grandhi, Shaoyang Wang, Bora Baydin, Basheer Al-Anesi, L. Krishnan Jagadamma, Paola Vivo.
Adv Devices Instrum.2024;5:0048.
The study investigates the necessity of doping Spiro-OMeTAD in lead halide perovskite (LHP) indoor photovoltaics (IPVs). It concludes that undoped Spiro-OMeTAD can achieve high efficiency and stability under low-light conditions, rivaling doped counterparts, suggesting that dopants may not be essential for effective IPV performance.
How Litos Lite was used
Litos Lite was utilized to perform J–V reverse and forward sweeps (scan rate 50 mV s−1), maximum power point (MPP) tracking, and stable power output (SPO) measurements on the prepared photovoltaic cells. These measurements were conducted under both simulated sunlight (AM 1.5G, 1-Sun, 100 mW cm−2) and indoor WLED illumination (5,000 lux, ≈1.60 mW cm−2) in N2 atmosphere. The indoor MPP tracking was performed either under continuous illumination or in 8-hour light–16-hour dark cycles .
How Paios was used
Transient photovoltage and transient photocurrent measurement were carried out with the all-in-one characterization platform, Paios.
Zhang, Z., Wang, L., Bi, H., Baranwal, A. K., Kapil, G., Sanehira, Y., Liu, J., Liu, D., Shen, Q., Hayase, S.,
Adv. Optical Mater. 2023, 2300962.
https://doi.org/10.1002/adom.202300962
To enhance the efficiency of tin halide perovskite solar cells (PKSCs), researchers addressed defects like Sn4+ and iodide vacancies by introducing copper iodide (CuI) doping. A preprocessing method for CuI improved perovskite layer quality, resulting in efficiency increases from 9.8% to 13.1% for P-I-N structures and 9.4% to 10.5% for hole transport layer (HTL)-free structures. These doped tin-PKSCs also exhibited improved stability, retaining 75% of their initial power conversion efficiency after 102 days of storage.
How Paios was used
Intensity-modulated photovoltage spectroscopy (IMVS), Intensity-modulated photovoltage spectroscopy (IMPS), Transient photovoltaic voltage (TPV), and Transient photovoltaic current (TPC) were carried out via PAIOS software.
Zhou, X., Yan, Y., Zhang, F. et al.
J Mater Sci: Mater Electron 34, 1415 (2023).
https://doi.org/10.1007/s10854-023-10838-4
To enhance the performance and stability of organic solar cells (OSCs), a binary anode buffer layer strategy was employed using molybdenum oxide (MoO3) and PEDOT:PSS. This improved work function and interface contact, increasing the power conversion efficiency (PCE) from 16.25% to 17.34%. Additionally, MoO3 prevented direct contact between PEDOT:PSS and ITO, enhancing device stability. This approach offers a simple and efficient method for high-efficiency, stable OSCs suitable for commercial applications.
Pengyu Su, Huan Bi, Du Ran, Li Liu, Wenjing Hou, Guangzhao Wang, Wenbing Shi,
Chemical Engineering Journal, Volume 472, 2023, 145077, ISSN 1385-8947,
https://doi.org/10.1016/j.cej.2023.145077
In a bid to enhance perovskite solar cell (PSC) performance and stability, a novel interfacial buffer layer called Ethyl p-nitrobenzoate (EPN) was introduced. EPN improved film quality, reduced defect density, relieved interfacial stress, and suppressed nonradiative recombination at the interface. This innovation led to a high 23.16% power conversion efficiency and improved device stability, showcasing the potential of multifunctional interfacial buffer layers in high-performance PSCs.
How Paios was used
TPC, TPV, IMPS, IMVS, and built-in potential were carried out via PAIOS in the structure of ITO/SnO2/(EPN)/perovskite/Spiro-OMeTAD/Ag, and the results were fitted using the companion software of PAIOS.
Montecucco, R., Pica, G., Romano, V., De Boni, F., Cavalli, S., Bruni, G., Quadrivi, E., De Bastiani, M., Prato, M., Po, R. and Grancini, G. (2023),
Sol. RRL 2300358.
https://doi.org/10.1002/adfm.202306040
All-inorganic perovskites show potential for creating stable and high-performing perovskite solar cells (PSCs). But, the high annealing temperature required for CsPbI3 stabilization limits its scalability for industrial production. This research introduces a method to stabilize CsPbI3ₓBrx perovskite at a reduced annealing temperature of 180°. This is achieved by using dimethylammonium (DMA) additives and bromide, facilitating the conversion to CsPbI3ₓBrx. Solar cells produced this way reached a power conversion efficiency (PCE) of 14.86%, outperforming the reference device. Using different halides in DMA salt for higher temperature annealing also proved beneficial, yielding an impressive PCE of 16.23%. This method, by lowering processing temperature, extends the utility of all-inorganic PSCs for industrial use and temperature-sensitive materials.
How Litos Lite was used
The stability measurements were performed at the MPP under N2 inert atmosphere and ambient temperature using Litos Lite coupled with a solar simulator continuously illuminating the devices. The spectrum used for the stability measurements was the same as the current density–voltage measurements.
Yi Yang, Jingwen Wang, Yunfei Zu, Qing Liao, Shaoqing Zhang, Zhong Zheng, Bowei Xu, Jianhui Hou,
Robust and hydrophobic interlayer material for efficient and highly stable organic solar cells,
Joule, Volume 7, Issue 3, 2023, Pages 545-557, ISSN 2542-4351,
https://doi.org/10.1016/j.joule.2023.02.013
A robust, hydrophobic electron transporting interlayer for organic solar cells (OSCs) is designed using a cross-linkable naphthalene diimide (NDI) derivative. The non-polar electron donor PCy2 is used to n-dope the crosslinked c-NDI:PCy2 film, increasing its doping density and conductivity.
This hydrophobic interlayer protects the device against water, resulting in excellent water resistance. With the c-NDI:PCy2 interlayer, a power conversion efficiency of 17.7% is achieved, which is the highest for OSCs with an inverted device architecture. Notably, this OSC can be used underwater, maintaining 70% of its initial efficiency after 1,000 hours in the dark or 4 hours under continuous illumination.
Andrés-Felipe Castro-Méndez, Jamie P. Wooding, Selma Fairach, Carlo A. R. Perini, Emily K. McGuinness, Jacob N. Vagott, Ruipeng Li, Sanggyun Kim, Vivek Brahmatewari, Nicholas Dentice, Mark D. Losego, and Juan-Pablo Correa-Baena
ACS Energy Lett. 2023, 8, 1, 844–852
Publication Date: January 3, 2023
https://doi.org/10.1021/acsenergylett.2c02272
This study investigates the use of vapor phase infiltration (VPI) to improve the stability of organic charge transport layers, such as hole-selective spiro-OMeTAD in perovskite solar cells (PSCs) and other organic electronic devices.
By using X-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), and grazing incident wide-angle X-ray scattering (GIWAXS), the study identifies that infiltration of TiOx via VPI hinders the crystallization of the spiro-OMeTAD layer. The infiltrated PSCs retained over 80% of their original efficiency after an operando stability test of 200 hours at 75°C, double the efficiency retained by devices without infiltration. This study suggests VPI can be used to stabilize organic charge transport layers and prolong device lifetimes.
Device stability measurements were carried out by tracking the maximum power point (MPP) of the devices while keeping constant the temperature of the films (by Peltier pads) at 75 °C using the stability measurement platform Litos from Fluxim.
Carlo Andrea Riccardo Perini, Esteban Rojas-Gatjens, Magdalena Ravello, Andrés-Felipe Castro-Mendez, Juanita Hidalgo, Yu An, Sanggyun Kim, Barry Lai, Ruipeng Li, Carlos Silva-Acuña, and Juan-Pablo Correa-Baena
Adv. Mater. 2022, 34, 2204726
https://doi.org/10.1002/adma.202204726
This study investigates the impact of bulky-cation-modified interfaces on the stability of halide perovskite solar cells, which has not been extensively explored. The research demonstrates the thermal instability of these interface layers used in state-of-the-art solar cells and reveals changes in the chemical composition and structure of the films under thermal stress, which affects charge-carrier dynamics and device operation. The type of cation used for surface treatment also affects the extent of these changes, with long carbon chains providing more stable interfaces. The study emphasizes the importance of prolonged annealing of the treated interfaces to enable reliable reporting of performance and inform the selection of different bulky cations.
Device Characterization: The photovoltaic performance was evaluated using a Fluxim Litos Lite setup, equipped with a Wavelabs Sinus-70 AAA solar simulator with AM1.5 spectrum for excitation.
Aging tests were performed using a Fluxim Litos setup, using 1 Sun equivalent illumination with no UV-component, holding the substrates at 55 °C in a N2 atmosphere and using an MPP tracking algorithm. Every 12 h, a J–V scan in reverse and forward direction was automatically acquired.
Steele, J.A., Braeckevelt, T., Prakasam, V. et al.
Nat Commun 13, 7513 (2022).
https://doi.org/10.1038/s41467-022-35255-9
The black perovskite phase of CsPbI3 is promising for optoelectronic applications; however, it is unstable under ambient conditions, transforming within minutes into an optically inactive yellow phase, a fact that has so far prevented its widespread adoption.
In this paper the research team present an effective strategy for embedding an interfacial microstructure (a PbI2 microgrid) into stable CsPbI3 perovskite thin films and devices, using a coarse photolithographic approach. The microgrid is shown to dramatically increase the long-term stability of black CsPbI3 thin films (beyond 2.5 years in a dry environment) by increasing the phase transition energy barrier (Eb) and limiting the spread of potential yellow phase formation to a single, isolated domain of the grid.
Using stabilized photodetectors, integration of a microgrid into normally unstable planar CsPbI3 perovskite devices is shown to be a simple and effective strategy toward stable ambient operation.
Paios was used to measure the rise and decay time and the capacitance of the devices. The pulsed J-V characteristics were measured from 2 V to −1 V with 50 ms, 1 ms, and 25 ms as the pulse length, rise time, and measurement time, respectively.
Fan, B., Gao, W., Wu, X. et al.
Nature Communications 13, 5946 (2022).
doi.org/10.1038/s41467-022-33754-3
Power conversion efficiency and long-term stability are two critical metrics for evaluating the commercial potential of organic photovoltaics.
Although the field has witnessed a rapid progress of efficiency towards 19%, the intrinsic trade-off between efficiency and stability is still a challenging issue for bulk-heterojunction cells due to the very delicate crystallization dynamics of organic species. Herein, the research team from the City University of Hon Kong developed a class of non-fullerene acceptors with varied side groups as an alternative to aliphatic chains.
Delay-time charge extraction by linearly increasing voltage (CELIV) was measured on the all-in-one platform of Paios (FluximAG). A light pulse with duration of 50 μs generated from an 810 nm LED lamp (light intensity 100%) was applied prior to a voltage ramp of 1 V μs–1.
The delay time between light pulse and voltage ramp was varied from 0.2 to 10 μs. During the delay time, the open circuit was kept by applying the transient photovoltage signal to ensure no current is flowing.
Qiwei Xu, I. Teng Cheong, Hanfa Song, Vien Van, Jonathan G. C. Veinot, and Xihua Wang
ACS Photonics 2022, 9, 8, 2792–2801
doi/pdf/10.1021/acsphotonics.2c00587
Integrating lead sulfide (PbS) colloidal quantum dots (CQDs) with crystalline silicon (c-Si) has been proven to be an effective strategy in extending the sensitivity of Si-based photodetectors into infrared regime. Here, the research team demonstrate the successful integration of PbS CQD inks with Si and construct a highly efficient heterojunction infrared photodiode operating in the range from 800 up to 1500 nm.
Summary points:
∙PbS CQD on Si to increase sensitivity of Si to IR
∙CQD:Si photodetector operating from 800 to 1500 nm
∙Layer of p-type QD enhances built-in electric field
∙EQE of 44% at 1280nm and 2V reverse bias - stable for more than 600 h
∙Photoresponse lower than 4μs without tails indicate low trap density
Lead sulfide (PbS) colloidal quantum dots (CQD) enable Si photodector sensitivity in the near infrared (NIR) in the range from 800 to 1500 nm.
The group of Xihua Wang at the University of Alberta achieved this result by spin-coating PbS CQD to form a CQD:Si heterojunction photodetector. The addition of a p-type CQD buffer layer at the CQD:Si interface enhanced the built-in electric field and improved the charge extraction. With transient photocurrent (TPC) and photovoltage (TPV) they measured a photoresponse lower than 4μs demonstrating low trap density at the CQD:Si interface.
TPC and TPV measurements were possible thanks to the all-in-one characterization platform PAIOS from Fluxim AG.
Haibing Xie, Zaiwei Wang, Zehua Chen, ..., Michael Gratzel,
Anders Hagfeldt, Monica Lira-Cantu et al.
Joule Volume 5, Issue 5, 19 May 2021, Pages 1246-1266
doi.org/10.1016/j.joule.2021.04.003
"Add H3pp to perovskite to improve performance while maintaining high efficiency (21% maintained after 1000 h @ MPP).
Perform various characterization and simulation techniques to demonstrate that the addition of H3pp leads to a passivation of the shallow defects, which are not affecting the performance but the device stability."
Voc vs L was performed using Paios to demonstrate negligible difference in n_id -> no difference in SRH.
C-f was carried out to demonstrate an effective reduction in ion migration and charge accumulation in the better device.
TPC and OCVD confirm negligible changes in the charge transport mechanism.
Chin-Yiu Chan, Masaki Tanaka, Yi-Ting Lee, Yiu-Wing Wong, Hajime Nakanotani, Takuji Hatakeyama, and Chihaya Adachi
Nature Photonics, 15, 203–207, (2021)
https://www.nature.com/articles/s41566-020-00745-z
It is challenging to produce stable blue OLEDs with high efficiency and color purity. The researchers fabricated a new OLED showing pure-blue emission with high efficiency and stability. Their optimized device consists of a 2-unit stacked tandem OLED with a hyperfluorescent emitting layer. Setfos was used to fit angular photoluminescence data and determine the orientation of the dipoles of the TADF emitter.
Z. Chen, J. Wang, H. Jin, J. Yang, Q. Bao, Z. Ma, W. Tress and Z. Tang
J. Mater. Chem. C (2021)
https://pubs.rsc.org/en/content/articlelanding/2021/tc/d1tc00745a
The authors studied the impact of the resistance of a sol-gel-grown ZnO interlayer on the efficiency of an organic solar cell. They find that the UV-induced doping effect leads to a significantly reduced ZnO resistance, which gives rise to an underestimated photoactive area and thus overestimated short-circuit current density (Jsc) Therefore, the validity of the argument that high-resistance interlayers do not lead to overestimated Jsc should always be carefully evaluated. Current-voltage characteristics were simulated using the large-area semiconductor simulator LAOSS