"W-shaped" injection current dependence of electroluminescence linewidth in green InGaN/GaN-based LED grown on silicon substrate
"W-shaped" injection current dependence of electroluminescence linewidth in green InGaN/GaN-based LED grown on silicon substrate
复制标题
硅衬底上生长的绿色 InGaN/GaN 基 LED 电致发光线宽的“W 形”注入电流依赖性
DOI：
10.1364/oe.25.00a871
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发表时间：
2017-10-02
期刊：
影响因子：
3.8
通讯作者：
Xu, Xiangang
中科院分区：
文献类型：
--
作者：
Li, Jianfei;Li, Changfu;Xu, Xiangang
在较宽的注入电流 (0.5 μA-350 mA) 和温度 (6-350 K) 范围内研究了生长在 Si 衬底上的绿色 InGaN/GaN 多量子阱 (MQW) 发光二极管 (LED) 的注入电流和温度以及电致发光 (EL) 光谱的依赖性。结果表明，温度升高会导致初始电流范围内 EL 光谱的注入电流相关行为发生变化。也就是说，随着低电流范围内注入电流的增加，MQW的发射过程在6 K左右的低温范围内以低能局域态的填充效应为主，在160 K左右的中间温度范围内以量子限制斯塔克效应的库仑屏蔽为主，随后以高能级的低能局域态的填充效应为主。然而，当温度进一步升高到350 K左右的较高温度范围时， MQW在低电流范围内的发射过程主要是载流子散射效应，然后是非辐射复合过程。上述EL光谱的电流依赖性行为主要归因于绿色LED的强烈局域效应，这一点可以通过在5μA的低注入电流下测得的EL光谱的反常温度依赖性得到证实。此外，不同温度下外量子效率的注入电流依赖性表明，随着温度从6增加到350 K，除了增强的非辐射复合外，电子溢出变得更加显着，特别是在300 K以上的较高温度范围内。 (C) 2017年美国光学学会
Injection current, and temperature, dependences of the electroluminescence (EL) spectrum from green InGaN/GaN multiple quantum well (MQW)-based light-emitting diodes (LED) grown on a Si substrate, are investigated over a wide range of injection currents (0.5 mu A-350 mA) and temperatures (6-350 K). The results show that an increasing temperature can result in the change of injection current-dependent behavior of the EL spectrum in initial current range. That is, with increasing the injection current in the low current range, the emission process of the MQWs is dominated by filling effect of low-energetic localized states at the low temperature range of around 6 K, and by Coulomb screening of the quantum confinement Stark effect followed by a filling effect of the higher levels of the low-energetic localized states at the intermediate temperature range of around 160 K. However, when the temperature is further raised to the higher temperature range of around 350 K, the emission process of the MQWs in the low current range is dominated by carrier-scattering effect followed by non-radiative recombination process. The aforementioned current-dependent behaviors of the EL spectrum are mainly attributed to the strong localized effect of the green LED, as confirmed by the anomalous temperature dependence of the EL spectrum measured at the low injection current of 5 mu A. In addition, the injection current dependence of external quantum efficiency at different temperatures shows that, with increasing temperature from 6 to 350 K, in addition to the enhanced non-radiative recombination, electron overflow becomes more significant, especially in the higher temperature range above 300 K. (C) 2017 Optical Society of America