Temperature-dependent efficiency droop behaviors of GaN-based green light-emitting diodes  

作　　者：江蓉 陆海 陈敦军 任芳芳 闫大为 张荣 郑有炓 

机构地区：[1]Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, and School of Electronic Science and Engineering, Nanjing University [2]Key Laboratory of Advanced Process Control of the Light Industry (Ministry of Education), Department of Electronic Engineering, Jiangnan University

出　　处：《Chinese Physics B》2013年第4期500-503,共4页中国物理B（英文版）

基　　金：Project supported by the State Key Program for Basic Research of China (Grant Nos. 2010CB327504, 2011CB301900, and 2011CB922100);the National Natural Science Foundation of China (Grant Nos. 60825401, 60936004, and 11104130);the Natural Science Foundation of Jiangsu Province, China (Grant Nos. BK2012110, BK2011556, and BK2011050)

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.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.

关 键 词：GAN green light-emitting diode efficiency droop ELECTROLUMINESCENCE 

分 类 号：TN312.8[电子电信—物理电子学]