Nanomaterials (Jul 2022)

Solid Phase Epitaxy of Single Phase Two-Dimensional Layered InSe Grown by MBE

  • Chia-Hsing Wu,
  • Yu-Che Huang,
  • Yen-Teng Ho,
  • Shu-Jui Chang,
  • Ssu-Kuan Wu,
  • Ci-Hao Huang,
  • Wu-Ching Chou,
  • Chu-Shou Yang

DOI
https://doi.org/10.3390/nano12142435
Journal volume & issue
Vol. 12, no. 14
p. 2435

Abstract

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Single-phase two-dimensional (2D) indium monoselenide (γ-InSe) film is successfully grown via solid phase epitaxy in the molecular beam epitaxy (MBE) system. Having high electron mobility and high photoresponsivity, ultrathin 2D γ-InSe semiconductors are attractive for future field-effect transistor and optoelectronic devices. However, growing single-phase γ-InSe film is a challenge due to the polymorphic nature of indium selenide (γ-InSe, α-In2Se3, β-In2Se3, γ-In2Se3, etc.). In this work, the 2D α-In2Se3 film was first grown on a sapphire substrate by MBE. Then, the high In/Se ratio sources were deposited on the α-In2Se3 surface, and an γ-InSe crystal emerged via solid-phase epitaxy. After 50 min of deposition, the initially 2D α-In2Se3 phase was also transformed into a 2D γ-InSe crystal. The phase transition from 2D α-In2Se3 to γ-InSe was confirmed by Raman, XRD, and TEM analysis. The structural ordering of 2D γ-InSe film was characterized by synchrotron-based grazing-incidence wide-angle X-ray scattering (GIWAXS).

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