Precise Layer-Dependent Electronic Structure of MBE-Grown PtSe2

Lei Zhang, Tong Yang, Muhammad Fauzi Sahdan, Arramel, Wenshuo Xu, Kaijian Xing, Yuan Ping Feng, Wenjing Zhang, Zhuo Wang, Andrew T.S. Wee

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13 Citations (Scopus)

Abstract

2D platinum diselenide (PtSe2) has received significant attention for 2D transistor applications due to its high carrier mobility. Here, using molecular beam epitaxy, the growth of 2D PtSe2 is investigated on highly oriented pyrolytic graphite (HOPG) and their electronic properties are unveiled via X-ray photoelectron spectroscopy, Raman spectra, and scanning tunnelling microscopy/spectroscopy as well as density functional theory (DFT) calculations. PtSe2 adopts a layer-by-layer growth mode on HOPG and shows a decreasing bandgap with increasing layer number. For the layer numbers from one to four, PtSe2 has bandgaps of 2.0 ± 0.1, 1.1 ± 0.1, 0.6 ± 0.1, and 0.20 ± 0.1 eV, respectively, and becomes semimetal from the fifth layer. DFT calculations reproduce the layer-dependent evolution of both the bandgap and band edges, suggest an indirect bandgap structure, and elucidate the underlying physics at the atomic level.

Original languageEnglish
Article number2100559
Number of pages7
JournalAdvanced Electronic Materials
Volume7
Issue number11
DOIs
Publication statusPublished - Nov 2021

Keywords

  • 2D materials
  • density functional theory calculations
  • molecular beam epitaxy
  • platinum diselenide
  • scanning tunneling microscopy/spectroscopy

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