Crystals (Oct 2021)

Investigation of Micromorphology and Carrier Recombination Dynamics for InGaN/GaN Multi-Quantum Dots Grown by Molecular Beam Epitaxy

  • Xue Zhang,
  • Wenxian Yang,
  • Zhiwei Xing,
  • Haibing Qiu,
  • Ying Gu,
  • Lifeng Bian,
  • Shulong Lu,
  • Hua Qin,
  • Yong Cai,
  • Yuta Suzuki,
  • Sakuya Kaneko,
  • Yuki Matsuda,
  • Shinji Izumi,
  • Yuichi Nakamura,
  • Atsushi Tackeuchi

DOI
https://doi.org/10.3390/cryst11111312
Journal volume & issue
Vol. 11, no. 11
p. 1312

Abstract

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InGaN quantum dots (QDs) are promising candidates for GaN-based all-visible optoelectronic devices such as micro light-emitting diode and laser. In this study, self-assembled InGaN/GaN multi-quantum dots (MQDs) have been grown by plasma-assisted molecular beam epitaxy on c-plane GaN-on-sapphire template. A high density of over 3.8 × 1010 cm−2 is achieved and InGaN QDs exhibit a relatively uniform size distribution and good dispersity. Strong localization effect in as-grown InGaN QDs has been evidenced by temperature-dependent photoluminescence (PL). The variation of peak energy is as small as 35 meV with increasing temperature from 10 K to 300 K, implying excellent temperature stability of emission wavelength for InGaN MQDs. Moreover, the radiative and nonradiative recombination times were calculated by time-resolved PL (TRPL) measurements, and the temperature dependence of PL decay times reveal that radiative recombination dominates the recombination process due to the low dislocation density of QDs structure.

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