Deep-to-shallow level transition of Re and Nb dopants in monolayerMoS2with dielectric environments

Abstract

We investigate the effects of dielectric environments on the transition levels of Re and Nb dopants in monolayer ${\mathrm{MoS}}_{2}$ through density functional theory calculations. The inherently weakly screened Coulomb interaction in free-standing monolayer ${\mathrm{MoS}}_{2}$ makes the dopant electrons and holes strongly bound, and the Re and Nb impurities are found to produce deep levels. It is shown that when the monolayer ${\mathrm{MoS}}_{2}$ is placed near high permittivity dielectrics the screened Coulomb interaction induces carrier delocalization with generating shallow levels.