Measurement of the light efficiency of organic LEDs (OLED)

Task

Long-time data aquisition at up to 120 OLEDs simultaneously. Determination of light intensity and resulting light efficiency of each OLED separately. Assembly of the test bed into a climatic chamber for simulation of several climatic conditions and for defined climatic stress of the test samples.

Requirements

• Measurement data aquisition with 240 channels (2 channels for each OLED)
• Semiautomatic calibration of equal light intensity of the OLEDs before test run
• Verification and saving the data on the computer
• Graphical visualization of the measurement data (during measurement or off-line)
• PASS/FAIL-Checking by measuring the light intensity divergence
• Simple adaption of the software for future requirements
• Taking out of test samples during test run for analytical purposes
• Off-line data analysis with commercial software

Solution

Writing of a measurement application with LabVIEW (National Instruments). Controlling of the measurement devices (Switch System / DMM from Keithley Instruments) via GPIB. Use of ambitious graphic visualizing possibilities (OLED selection, ZoomIn, ZoomOut). Evaluated measurement data are saved as spreadsheet ascii file.