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arXiv · 2105.03334

Precise Layer-Dependent Electronic Structure of MBE-Grown PtSe$_2$

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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Abstract

Two-dimensional (2D) platinum diselenide (PtSe$_2$) has received significant attention for 2D transistor applications due to its high mobility. Here, using molecular beam epitaxy, we investigate the growth of 2D PtSe$_2$ on highly oriented pyrolytic graphite (HOPG) and unveil their electronic properties via X-ray photoelectron spectroscopy, Raman spectra, and scanning tunnelling microscopy/spectroscopy as well as density functional theory (DFT) calculations. PtSe$_2$ adopts a layer-by-layer growth mode on HOPG and shows a decreasing band gap with increasing layer number. For the layer numbers from one to four, PtSe$_2$ has band gaps of $2.0 \pm 0.1$, $1.1 \pm 0.1$, $0.6 \pm 0.1$ and $0.20 \pm 0.1$ eV, respectively, and becomes semimetal from the fifth layer. DFT calculations reproduce the layer-dependent evolution of both the band gap and band edges, suggest an indirect band-gap structure, and elucidate the underlying physics at the atomic level.

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Lei Zhang, Tong Yang, Muhammad Fauzi Sahdan, Arramel, Wenshuo Xu, Kaijian Xing, Yuan Ping Feng, Wenjing Zhang, Zhuo Wang, Andrew T. S. Wee. 2021-05-07. Precise Layer-Dependent Electronic Structure of MBE-Grown PtSe$_2$. https://arxiv.org/abs/2105.03334

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