Investigation of Thermal Effect on Reliability and Chromaticity Shift in QD-LEDs Displays

Abstract

In this work, thermal effect on reliability and chromaticity shift in quantum dots (QDs)-based light emitting diodes (LEDs) are investigated by long term lifetime test and IR thermal image. The results have suggested that the heat power generation during luminescence conversion process play a key role in the compatibility between QD and encapsulation resin, which is correlated to the blue luminescence intensity generated from LED chip and the QD luminescence intensity converted by QDs. The ligands detachment of QD at luminescence conversion process results in poor reliability of QDs and influence on the thermal load ability of encapsulation resin, whereas the condition of QD should be a dominant factor. It was also found that QD with thicker shell could prevented heat power generation since higher conversion efficiency and better stability, shown the better reliability of QD-LEDs and less chromaticity shift.