Chin. Phys. B ›› 2013, Vol. 22 ›› Issue (4): 47805-047805.doi: 10.1088/1674-1056/22/4/047805
• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇 下一篇
江蓉a, 陆海a, 陈敦军a, 任芳芳a, 闫大为b, 张荣a, 郑有炓a
Jiang Rong (江蓉)a, Lu Hai (陆海)a, Chen Dun-Jun (陈敦军)a, Ren Fang-Fang (任芳芳)a, Yan Da-Wei (闫大为)b, Zhang Rong (张荣)a, Zheng You-Dou (郑有炓)a
摘要: The efficiency droop behaviors of GaN-based green light emitting diodes (LEDs) are studied as a function of temperature from 300 K to 480 K. The overall quantum efficiency of the green LEDs is found to degrade as temperature increases, which is mainly caused by activation of new non-radiative recombination centers within the LED active layer. Meanwhile, the external quantum efficiency of the green LEDs starts to decrease at low injection current level (<1 A/cm2) with a temperature-insensitive peak-efficiency-current. In contrast, the peak-efficiency-current of a control GaN-based blue LED shows continuous up-shift at higher temperatures. Around the onset point of efficiency droop, the electroluminescence spectra of the green LEDs also exhibit a monotonic blue-shift of peak energy and a reduction of full width at half maximum as injection current increases. Carrier delocalization is believed to play an important role in causing the efficiency droop in GaN-based green LEDs.
中图分类号: (III-V semiconductors)