February, 2004

EEEL Helps Dupont with Measurement of OLEDs
Researchers in the EEEL Display Metrology Project collaborated with Dupont Displays (Santa Barbara, CA) in an investigation of the scalability of reflection measurements in OLEDs (organic light-emitting diode displays or materials) with attention to fluorescence. Difficulties in the characterization of OLED performance for sunlight readability arise because of the expense and difficulty of providing the proper sunlight-level illumination and the correct solar spectrum. A less expensive alternative is to use lower-light-level illumination under stable laboratory conditions to measure a display's readability and then scale the results to sunlight levels. However, regarding OLEDs, there is a concern that the fluorescence typically encountered with many such displays may exhibit saturation at sunlight levels. If florescence saturation were to occur it would prevent using scalable reflection measurements and require full sunlight illuminance and spectrum to perform an accurate characterization. It was demonstrated that that the OLED fluorescence was, indeed, linear and scalable even up to illuminance levels of equal to the magnitude of several suns. It is therefore possible to make laboratory reflection measurements with much lower illuminance levels and scale them to appropriate sunlight levels to qualify such displays for sunlight readability. Results are to be reported at the Society for Information Display Symposium in Seattle, WA in May 2005.

Contact:

Paul Boynton, (301) 975-3014