In two-dimensional van der Waals crystals, the interlayer stacking sequence often leads to a change in crystal symmetry and, thus, new polymorphs, leading to an abundant array of physical properties. In this paper, we report the polymorphic form of 2H–3R–NbSe2 that exhibits a substantial difference in terms of the gate dependence of semimetallic behavior and Seebeck coefficient, compared to the well-known 2H–NbSe2 with metallic transport behavior. The semimetallic features of 2H–3R–NbSe2 indicate the presence of minor carriers, confirmed through theoretical calculations, which is in good agreement with the transport behavior. Our results reveal perspectives for understanding the metastable 2H–3R phase NbSe2, which is not far from equilibrium, and for engineering the materials necessary for efficient energy harvesting.
Bibliographical noteFunding Information:
This work was supported by the Agency for Defense Development Republic of Korea ( UD170089GD ) and the Priority Research Centers Program through the National Research Foundation of Korea (NRF) ( 2019R1A6A1A11055660 ). J.K. also acknowledges supports from the DGIST R&D Program ( 20-ET-07 ) and Basic Science Research Program ( NRF - 2019R1I1A1A01063687 ).
© 2020 Elsevier Ltd
All Science Journal Classification (ASJC) codes
- Renewable Energy, Sustainability and the Environment
- Materials Science(all)
- Electrical and Electronic Engineering