Jiadong Zhou1#, Xianghua Kong2,3#, Chandra Mutyala4,5#, Junhao Lin6*, Rui Xu3,7, Xiaowei Wang1, Yu Chen8, Yao Zhou8, Chao Zhu1, Wei Lu4,5, Fucai Liu1, Bijun Tang1, Chao Zhu1, Zhihai Cheng3,7, Ting Yu8, Kazu Suenaga9, Dong Sun4,5*, Wei Ji3*, and Zheng Liu1
1Center for Programmable Materials, School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore.
2Department of Physics and Centre for the Physics of Materials, McGill University, Montreal, Canada H3A 2T8
3Department of Physics and Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-nano Devices, Renmin University of China, Beijing 100872, China
4International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, People’s Republic of China
5Collaborative Innovation Center of Quantum Matter, Beijing 100871, People’s Republic of China
6Department of Physics, Southern University of Science and Technology, Shenzhen 518055, People’s Republic of China.
7CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing100190, China
8Centre for Disruptive Photonic Technologies, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
9National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 3058565, Japan
10Centre for Micro-/Nano-electronics (NOVITAS), School of Electrical & Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
11CINTRA CNRS/NTU/THALES, UMI 3288, Research Techno Plaza, 50 Nanyang Drive, Border X Block, Level 6, Singapore 637553, Singapore
# J.Z., X.K. and C.M. contributed equally to this work
Corresponding authors: Z.L. (email: email@example.com), W. J. (email: firstname.lastname@example.org), D. S. (email: email@example.com), J.H.L (email: firstname.lastname@example.org)
DOI:10.1021/acsnano.8b09479 Publication Date: 27 September 2019
PtSe2, a new layered two-dimensional material, has drawn intensive attention owing to its layer-dependent band structure, high air stability and spin-layer locking effect which embraces the applications for next-generation optoelectronic, electronic devices and catalysis. However, synthesis of large monolayer PtSe2 single crystal is challenging due to the low chemical reactivity of Pt sources. Here, we report the synthesis of monolayer PtSe2 single crystal via epitaxy growth on MoSe2 by a one-step chemical vapor deposition (CVD) method. The underlying MoSe2 substrate plays a key role for the monolayer growth of PtSe2. The periodic Moiré patterns from the vertically stacked heterostructure (PtSe2/MoSe2) are clearly identified via annular dark-field scanning transition electron microscopy (ADF-STEM). First-principles calculations show a type II band alignment and reveal interface states originating from the Strong-Weak Interlayer Coupling (S-WIC) between PtSe2 and MoSe2 monolayers, as demonstrated by the electrostatic force microscopy (EFM) observed edge states. Ultrafast transient dynamics of photoexcited carrier in PtSe2/MoSe2 heterostructure show ultrafast hole transfer between PtSe2 and MoSe2 monolayers, which matches well with the theoretical results. Our study opens a new way to synthesize uniform PtSe2 monolayers and other Pt-based heterostructures. These results also shed considerable lights on optoelectronics in vdW solids consisting of weak and strong interlayer coupled materials.