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

• We investigated the magnetic and optical properties of the WSe2/VSe 2 heterostructure. • The Curie temperature was substantially enhanced to 380 K in the heterostructure. • The refractive index in was greatly increased to 2.85. • We obtained the transmission coefficient larger than 0.7 in the heterostructure. 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-VSe 2 monolayer and WSe 2 /VSe 2 heterostructure. Both VSe 2 monolayer and WSe 2 /VSe 2 heterostructure showed ferromagnetic state ground state. The Curie temperature of the 1T-VSe 2 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 WSe 2 /VSe 2 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 TiO 2 . Overall, we find that the WSe 2 /VSe 2 heterostructure can be used for potential device applications as an optically transparent magnetic system at room temperature.