Optically transparent ferromagnetic 2D WSe2/VSe2 heterostructure with high Curie temperature and high refractive index

Abstract

An optically transparent low dimensional magnetic system has rarely been found in nature. Particularly, it is a real challenging issue to find an optically transparent two-dimensional magnetic material operating at room temperature with a high refractive index. Thus, we explored the magnetic and optical properties of the 1T-VSe2 monolayer and WSe2/VSe2 heterostructure. Both VSe2 monolayer and WSe2/VSe2 heterostructure showed ferromagnetic state ground state. The Curie temperature of the 1T-VSe2 monolayer was 250 K, and this was substantially enhanced to 380 K due to the increased exchange parameter in the heterostructure. We also found that the WSe2/VSe2 heterostructure displayed a refractive index of 2.85. Moreover, the optical transparency of the heterostructure reached more than 75 % in the visible range. The high refractive index and optical transparency of the heterostructure are comparable to those of bulk type TiO2. Overall, we find that the WSe2/VSe2 heterostructure can be used for potential device applications as an optically transparent magnetic system at room temperature.