Evolution mechanism of InGaN quantum dots and their optical properties
Evolution mechanism of InGaN quantum dots and their optical properties
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InGaN量子点的演化机制及其光学性质
DOI：
10.1016/j.optmat.2019.109554
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发表时间：
2020-01-01
影响因子：
3.9
通讯作者：
Wu, Yucheng
中科院分区：
文献类型：
--
作者：
Dong, Hailiang;Qu, Kai;Wu, Yucheng
采用金属有机物化学气相沉积法生长了InGaN自组装量子点。InGaN量子点的表面形貌进行了研究，为不同数量的周期范围内的1至5。利用相分离理论和有源区不同应变对InGaN量子点的界面形成机制进行了研究。用球差校正透射电子显微镜观察了富In局域态和界面原子像。此外，根据铟（In）原子迁移的生长动力学，讨论了InGaN量子点的形成机制。通过变温光致发光测试了类量子点的光学性质。这些结果表明，由于总累积应变的增加，内量子效率随着周期性的增加而增加。由于InGaN层中铟组分的波动，量子点自发形成。峰值能量随温度的变化是由InGaN/GaN有源区的尺寸不均匀性和载流子局域化引起的载流子动力学解释的。这些结果为制备高质量的InGaN量子点提供了实验数据和理论依据。
InGaN self-assembled quantum dots (QDs) have been grown by metal-organic chemical vapor deposition. The surface morphologies of InGaN QDs were investigated for different number of periods in the range of one to five. Interfacial formation mechanism of InGaN QDs was investigated by phase separation theory and different strain in active zone. In-rich localized states and interfacial atomic images were observed by spherical aberration corrected transmission electron microscopy. Furthermore, the formation mechanism of InGaN QDs was discussed according to growth kinetics of indium (In) atom migration. The optical properties of QDs-like were tested by temperature-dependent photoluminescence. These results show internal quantum efficiency increases with increasing periodicity owing to increasing total accumulated strain. QDs are formed spontaneously owing to indium composition fluctuations in InGaN layer. The variations of peak energy with increasing temperature are explained by carrier dynamics as a result of size inhomogeneity and carrier localization in InGaN/GaN active zone. These results provide experimental data and theoretical basis for fabricating high quality InGaN QDs.