Significant increase of quantum efficiency of green InGaN quantum well by realizing step-flow growth
Significant increase of quantum efficiency of green InGaN quantum well by realizing step-flow growth
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通过实现阶跃流生长显着提高绿色InGaN量子阱的量子效率
DOI：
10.1063/1.5001185
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发表时间：
2017
影响因子：
4
通讯作者：
Yang Hui
中科院分区：
文献类型：
--
作者：
Tian Aiqin;Liu Jianping;Zhang Liqun;Jiang Lingrong;Ikeda Masao;Zhang Shuming;Li Deyao;Wen Pengyan;Cheng Yang;Fan Xiaowang;Yang Hui
二维（2D）岛状形貌已被广泛报道用于绿色发光InGaN量子阱（QW）层，但迄今为止尚未获得用于绿色InGaN QW层的阶梯流形貌。在这封信中，我们首先调查的原因，二维岛形态的绿色InGaN量子阱通过比较研究与蓝色InGaN量子阱。在较低的生长温度下，吸附原子的短扩散长度被认为是导致二维岛状形貌的绿色InGaN量子阱。通过将c面GaN衬底的斜切角从0.20°增加到0.48°，减小了原子平台宽度，实现了绿色InGaN量子阱的阶梯流生长。发现具有阶梯流形貌的绿色InGaN/GaN多量子威尔斯（MQW）比具有二维岛状形貌的MQW具有更尖锐的阱/势垒界面。在一定的激发功率密度下，具有阶梯流形貌的绿色InGaN/GaN多量子阱的内量子效率是具有二维岛状形貌的相应多量子阱的两倍。
Two-dimensional (2D) island morphologies have been widely reported for green light-emitting InGaN quantum well (QW) layers, but the step-flow morphology has not been obtained for a green InGaN QW layer to date. In this Letter, we first investigate the cause of the 2D island morphology of green InGaN QWs via a comparison study with blue InGaN QWs. The short diffusion lengths of adatoms at low growth temperatures were found to be the cause of the 2D island morphology for the green InGaN QW. Step-flow growth of green InGaN QWs was obtained by increasing the miscut angle of the c-plane GaN substrates from 0.20° to 0.48°, which reduces the atomic terrace width. Green InGaN/GaN multiple quantum wells (MQWs) with step-flow morphologies were found to have sharper well/barrier interfaces than MQWs with 2D island morphologies. The internal quantum efficiency of the green InGaN/GaN MQWs with the step-flow morphology is double that of the corresponding MQWs with the 2D island morphology at an excitation power density...