Nanoscale Research Letters (Nov 2021)

The Atomic Rearrangement of GaN-Based Multiple Quantum Wells in H2/NH3 Mixed Gas for Improving Structural and Optical Properties

  • Yuhao Ben,
  • Feng Liang,
  • Degang Zhao,
  • Jing Yang,
  • Zongshun Liu,
  • Ping Chen

DOI
https://doi.org/10.1186/s11671-021-03618-8
Journal volume & issue
Vol. 16, no. 1
pp. 1 – 8

Abstract

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Abstract In this work, three GaN-based multiple quantum well (MQW) samples are grown to investigate the growth techniques of high-quality MQWs at low temperature (750 °C). Instead of conventional temperature ramp-up process, H2/NH3 gas mixture was introduced during the interruption after the growth of InGaN well layers. The influence of hydrogen flux was investigated. The cross-sectional images of MQW via transmission electron microscope show that a significant atomic rearrangement process happens during the hydrogen treatment. Both sharp interfaces of MQW and homogeneous indium distribution are achieved when a proper proportion of hydrogen was used. Moreover, the luminescence efficiency is improved strongly due to suppressed non-radiative recombination process and a better homogeneity of MQWs. Such kind of atomic rearrangement process is mainly caused by the larger diffusion rate of gallium and indium adatoms in H2/NH3 mixed gas, which leads to a lower potential barrier energy to achieve thermodynamic steady state. However, when excessive hydrogen flux is introduced, the MQW will be partly damaged, and the luminescence performance will deteriorate.

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