Overview

Litos is an advanced LED stability lifetime measurement system. It has 16, or 32 parallel stressing channels distributed over 4 chambers. The wide range of stress conditions and the possibility of interfacing Litos with Paios for in-depth degradation analysis, make it a primary choice for researchers that want to understand the degradation behaviour of organic, perovskite, and quantum-dots-based LEDs.

 

Advantages

  • 16, or 32 individual channels to address multiple LEDs in parallel.

  • 4 chambers with individual humidity sensors.

  • Design customized to the specific sample layout of the customer.

  • The Litos-Paios Integration provides a unique tool to study degradation mechanisms in LEDs.

  • User-friendly software for automatic measurement control and parameter extraction.

  • Stressing at constant current, constant luminance, and constant voltage

  • Compatible with Bottom and Top Emitting LEDs (1 chamber with either BT/TP photodetectors)

  • Individual photodiode for each LED under test (optical separation not possible).

  • Temperature control of the individual sample 0 – 85 °C.

 
 

Specifications

Independent stressing and characterization of up to 32 pixels in 4 chambers
Functionality JV(L), in-situ spectral measurements (PL and EL)
Operations All channels are electrically independent. Temperature controller on stage.
Voltage Range -9 V to 9 V
Maximum Current/Channel 60 mA /channel
Current Resolution Best/typical: 1 μA / 5 μA
Sample Size Up to 20mm diameter.
Sample Holder Custom-made. Photodetectors for top or bottom emission LEDs
Temperature Range 0 - 85°C
Computer Connection USB
 

Request a DEMO of LITOS


Sample Holder

Litos has 4 independent chambers to test simultaneously 4 samples with multiple pixels. The sample holders are custom-made according to the specific layout of our customers. The LEDs are in contact with 2 pins per sample.

Multiple sample holders with different layouts can be ordered and quickly replaced in the testing chamber by the user. Depending on the selected configuration, up to 8 LEDs can be stressed simultaneously in each chamber (32 devices in total).

The chamber can be equipped with photodiodes for either bottom-emission or top-emission LEDs. It is not possible to test both TOP/bottom devices in the same chamber. It is also possible to integrate a single spectrometer in each chamber.

An active cooling and heating system is available for each chamber. Each chamber has an individual temperature PID controller which has a temperature range of 0 °C to 85 °C.

 
 
 

Litos/Paios Integration

Paios and Litos can be connected and managed by the same software (Characterization Suite). In OLEDs, the simple luminance decay over time or steady-state analysis is not sufficient to draw meaningful conclusions. A more systematic strategy comprising a wider spectrum of experimental techniques is therefore required. A full characterization of the device during degradation can be performed automatically by combining Paios with Litos:

  • Understanding the degradation mechanisms of LEDs with an automated routine of stressing and analysis.

  • Current-Voltage (I-V) characteristics.

  • Transient measurements (CELIV, TEL …)

  • Impedance spectroscopy / CV.

  • All measurements can be performed as a function of the temperature ( 0°C to 85°C).

  • Dedicated stressing routines for OLEDs

Experimental results from Litos-Paios integration on TADF OLEDs. (a) Emission decay over time measured with Litos. (b) JV curve at different stressing times

 
degradation analysis of OLEDs and perovskite solar cells. sample holder with photodiodes and spectrometer