Efficiency and Droop Improvement in Hybrid Warm White LEDs Using InGaN and AlGaInP High-Voltage LEDs

Kuo-Ju Chen, Hsuan-Ting Kuo, Yen-Chih Chiang, Hsin-Chu Chen, Chao-Hsun Wang, Min-Hsiung Shih, Chien-Chung Lin, Ching-Jen Pan, Hao-Chung Kuo
2013 IEEE/OSA Journal of Display Technology  
This study investigates the optical and electrical characteristics in hybrid warm white high-voltage light-emitting diodes (HV-LEDs). The luminous efficiency of the hybrid warm white LED in this study improved by 11% and 51%, compared to conventional cool and warm LEDs, respectively, solving the warm white gap in white LEDs. The efficiency droop of the hybrid warm white LED was reduced to 21.8% from 26.8% for the conventional cool white LED, and from 26.3% in the conventional warm white LED at
more » ... 0 mA (35 A/cm ) the operated current. Furthermore, the color rendering index (CRI) and angular correlated color temperature (CCT) were analyzed, indicating a significant improvement in hybrid warm white HV-LEDs.
doi:10.1109/jdt.2012.2227054 fatcat:bwxvawbwazbkrclexgxmmk5a3a