B2S3monolayer: a two-dimensional direct-gap semiconductor with tunable band-gap and high carrier mobility.

Atomically two-dimensional materials with direct band-gap and high carrier mobility are highly desirable due to their promising applications in electronic devices. Here, on the basis ofab initiocalculations and global particle-swarm optimization method, we predict the B2S3monolayer as a new semiconductor with favorable functional properties. The B2S3monolayer possesses a high electron mobility of 553 cm2V-1s-1and a direct band-gap of 1.85 eV. The direct band-gap can be manipulated under biaxial strain. Furthermore, B2S3monolayer can absorb sunlight efficiently in the entire range of the visible light spectrum. Besides, this monolayer holds good dynamical, thermal, and mechanical stabilities. All the desired properties render B2S3monolayer a promising candidate for future applications in high-speed (opto)electronic devices.