Analysis of the Temperature Dependence of Phosphor Conversion Efficiency in White Light-Emitting Diodes

作者：Ryu Guen Hwan; Ryu Han Youl^*

来源：Journal of the Optical Society of Korea, 2015, 19(3): 311-316.

DOI：10.3807/JOSK.2015.19.3.311

• Light-emitting diode
• White LED
• Phosphor conversion efficiency

We investigate the temperature dependence of the phosphor conversion efficiency (PCE) of the phosphor material used in a white light-emitting diode (LED) consisting of a blue LED chip and yellow phosphor., The temperature dependence of the wall-plug efficiency (WPE) of the blue LED chip and the PCB of phosphor are separately determined by analyzing the measured spectrum of the white LED sample. As the ambient temperature increases from 20 to 80 degrees C, WPB and PCE decrease by about 4.5% and 6%, respectively, which means that the contribution of the phosphor to the thermal characteristics of white LEDs can be more important than that of the blue LED chip. When PCE is decomposed into the Stokes-shift efficiency and the phosphor quantum efficiency (QE), it is found that the Stokes-shift efficiency is only weakly dependent on temperature, while the QE decreases rapidly with temperature. From 20 to 80 degrees C the phosphor QE decreases by about 7% while the Stokes-shift efficiency changes by less than 1%.

• 出版日期2015-6