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, 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

LITOS DEMO and QUESTIONS

Sample Holder

Electrode Board on Top of the Sample

Transparent Lid of the Single Chamber

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