1. Influences of point defects on electrical and optical properties of InGaN light-emitting diodes at cryogenic temperature.
- Author
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Tu, Yi, Ruan, Yujiao, Zhu, Lihong, Tu, Qingzhen, Wang, Hongwei, Chen, Jie, Lu, Yijun, Gao, Yulin, Shih, Tien-Mo, Chen, Zhong, and Lin, Yue
- Subjects
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POINT defects , *ELECTRIC properties of indium gallium nitride , *OPTICAL properties of indium gallium nitride , *LIGHT emitting diode efficiency , *QUANTUM efficiency , *ELECTRIC resistance - Abstract
We investigate the cryogenic external quantum efficiency (EQE) for some InGaN light-emitting diodes with different indium contents. We observe a monotonic decrease in EQE with the increasing forward current before the “U-turn” point, beyond which the thermal effect increases the EQE. We discover positive dependences among the droop rate (
χ ), differential electrical resistance (Rd ), and indium content. Also,χ andRd of individual green samples shift correspondingly during the aging test, when the Mg ions are activated at high injection density and diffuse into the active region. Considering the fact that both In and Mg ions would introduce point defects (PDs), we proposed a model that reveals the mechanism of interplay between PDs and carriers. PDs serve as both energy traps and non-radiative recombination centers. They attract and confine carriers, leading to an increase inRd and a decrease in EQE. [ABSTRACT FROM AUTHOR]- Published
- 2018
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