Anomalous electroluminescent blue-shift behavior induced by well widths variance and localization effect in InGaN/GaN multi-quantum wells

作者：Peng, Liyuan; Zhao, Degang^*; Jiang, Desheng; Zhu, Jianjun; Liu, Zongshun; Chen, Ping; Yang, Jing; Liu, Wei; Liang, Feng; Xing, Yao; Liu, Shuangtao; Zhang, Liqun; Wang, Wenjie; Li, Mo; Zhang, Yuantao; Du, Guotong

来源：Optics Express, 2018, 26(17): 21736-21744.

DOI：10.1364/OE.26.021736

• TEMPERATURE-DEPENDENCE
• EPITAXIAL-GROWTH
• QUANTUM
• EMISSION
• ENERGY
• FILMS
• MODEL

Twelve InGaN MQW LED samples with varying well thickness grown via metalorganic chemical vaper deposition (MOCVD) are investigated. It is observed from electroluminescence (EL) measurement that at low current densities, the peak energy shifts to blue with increasing current, and when the current change by fixed increment, the peak energy shifts to blue end to different extent among samples. This blue shift was expected to be" stronger when the well thickness increases, however, for well widths above 5 nm we observe a decrease in emission energy. Since no relaxation was detected from reciprocal space mapping (RSM), the deteriorated homogeneity is found to be responsible for this phenomenon. Temperature dependent photoluminescence (TDPL) results analyzed by band-tail model fitting show that the localization effect gets more prominent with increasing well thickness. It is found that elevating the growth temperature of active region from 710 degrees C to 750 degrees C significantly improves the homogeneity of InGaN layer.

• 出版日期2018-8-20
• 单位中国科学院; 中国科学院苏州纳米技术与纳米仿生研究所; 吉林大学; 集成光电子学国家重点实验室; 中国科学院大学; 中国工程物理研究院