Author(s): Wang, YC (Wang, Yachen); Liang, F (Liang, Feng); Zhao, DG (Zhao, Degang); Ben, YH (Ben, Yuhao); Yang, J (Yang, Jing); Liu, ZS (Liu, Zongshun); Chen, P (Chen, Ping)

Source: CRYSTALS Volume: 12 Issue: 6 Article Number: 839 DOI: 10.3390/cryst12060839 Published: JUN 2022

Abstract: In this work, the photoluminescence (PL) properties of three as-grown InGaN/GaN multiple quantum well (MQW) structures which are heat-treated under different temperatures with nitrogen (N-2) atmosphere are investigated. Temperature-dependent photoluminescence (PL) analysis was used to characterize the depth of localized states and defect density formed in MQWs. By fitting the positions of luminescence peaks with an LSE model, we find that deeper localized states are formed in the MQWs after high-temperature treatment. The experimental results show that the luminescence intensity of the sample heat-treated at 880 degrees C is significantly improved, which may be due to the shielding effect of In clusters on defects. While the luminescence efficiency decreases because of the higher defect density caused by the decomposition of the InGaN QW layer when the sample is heat-treated at 1020 degrees C. Moreover, the atomic force microscope results show that the increase in heat-treatment temperature leads to an increase in the width of surface steps due to the rearrangement of surface atoms in a high-temperature environment.

Accession Number: WOS:000819628300001

eISSN: 2073-4352

Full Text: https://www.mdpi.com/2073-4352/12/6/839