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

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

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   

  1. a Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, and School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, China;
    b Key Laboratory of Advanced Process Control of the Light Industry (Ministry of Education), Department of Electronic Engineering, Jiangnan University, Wuxi 214122, China
  • 收稿日期:2012-09-10 修回日期:2012-09-28 出版日期:2013-03-01 发布日期:2013-03-01
  • 基金资助:
    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), and the Natural Science Foundation of Jiangsu Province, China (Grant Nos. BK2012110, BK2011556, and BK2011050).

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

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   

  1. a Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, and School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, China;
    b Key Laboratory of Advanced Process Control of the Light Industry (Ministry of Education), Department of Electronic Engineering, Jiangnan University, Wuxi 214122, China
  • Received:2012-09-10 Revised:2012-09-28 Online:2013-03-01 Published:2013-03-01
  • Contact: Lu Hai E-mail:hailu@nju.edu.cn
  • Supported by:
    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), and the Natural Science Foundation of Jiangsu Province, China (Grant Nos. BK2012110, BK2011556, and BK2011050).

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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.

关键词: GaN, green light-emitting diode, efficiency droop, electroluminescence

Abstract: 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.

Key words: GaN, green light-emitting diode, efficiency droop, electroluminescence

中图分类号:  (III-V semiconductors)

  • 78.55.Cr
85.60.Jb (Light-emitting devices) 78.60.Fi (Electroluminescence)