Lattice vibration properties of MoS2/PtSe2 heterostructures

In this study, large-area contiguous triplelayer PtSe2, monolayer MoS2, and MoS2/PtSe2 heterostructures were fabricated using chemical vapor deposition combined with the transfer technology. The temperature-dependent Raman spectrum demonstrates that the in-plane and out-of-plane PtSe2 -and MoS2 -related active modes all display red shift with increasing temperature. In addition, the temperature coefficient deduced from the MoS2/PtSe2 heterostructure is much smaller than the corresponding value obtained from the pristine MoS2 and PtSe2 films, demonstrating a better thermal stability of the heterostructure. A strong interlayer coupling in triplelayer PtSe2 and small thermal expansion mismatch together with the layer interaction between MoS2 and PtSe2 are ascribed to this softening of phonon shifts. Such study firstly contributes to the fundamental exploration of the lattice vibration properties of the MoS2/PtSe2 heterostructure and offers significant guidance for the PtSe2 -based device design and fabrication. (C) 2019 Elsevier B.V. All rights reserved.