Tunable Direct Semiconductor Gap and High Carrier Mobility of Mo6Br6S3 Monolayer

摘要

Two-dimensional materials with direct semiconductor gaps and high mobilities can play important role in future electronic and optical applications. Here, we propose that Mo6Br6S3 monolayer as a new two-dimensional material is stable and can be exfoliated from its corresponding layered bulk. Our first-principles results show that the monolayer has a direct semiconductor gap beyond 1 eV (between Perdew-Burke-Ernzerhof and Heyd-Scuseria-Ernzerhof values) and a very high electron mobility (6880 cm(2)/(V s)), and these can be tuned through in-plane strain by applying uniaxial stress. Furthermore, we show that the Mo6Br6S3/graphene heterostructure makes a p-type Schottky barrier and the amplitude of band bending (0.03 eV) is extremely low compared to that of other similar junctions because the Mo6Br6S3 monolayer has a close work function to that of graphene. With all of these useful properties and functions, the Mo6Br6S3 monolayer can be very promising for nanoelectronic and optical applications.