Tunable electronic structures, half-metallicity and optical properties in Fe-NM (NM=B, C, N) co-doped monolayer 2H-MoSe2

Exploring two-dimensional (2D) graphene-like materials with magnetic characteristics has attracted intense research interest. Here, based on spin-polarized density functional theory calculations, the tunable electronic structures, half-metallicity and optical properties can be realized in the 2D monolayer MoSe2 by Fe-NM (NM=B, C, N) codoping. The results indicate that the Fe-doping and Fe-B codoping exhibit a robust magnetic half-metallicity, which can be attributed to that the electrons partially occupy the bonding state consisting of Fe e(1) and Fe a(1) states at the Femi level (E-F). The Fe-N codoping exhibits a magnetic semiconductor character due to the strong hybridization between Fe d(xy), d(z)(2) states and N p(z) state. However, the Fe-C codoping shows a non-magnetic ground state due to the effective charge compensation between Fe and C atoms. The Fe-NM codoping can effectively tune the optical properties of monolayer MoSe2 by the introducing of impurity levels near the E-F. A stronger and wider absorption in the visible region of 1.8-3.2 eV is observed, which is in favor of the visible light devices and potential solar absorbers. The distinctive magnetic half-metallicity, electronic and optical properties for the Fe-NM co-doped monolayer MoSe2 have great prospects in the fields of spintronics, opto-electronics and magneto-optics devices. (C) 2019 Elsevier B.V. All rights reserved.