The quantum confinement effects on the electronic properties of monolayer GeS nanoribbon with tube-edged reconstruction

Abstract

Monolayer α-phase GeS is promising for many novel applications due to its high carrier mobility and suitable band gap. Recently, the metal and nonmetal zigzag edges of monolayer α-phase GeS have been predicted to undergo universal ZZ(Ge-Tube)/ZZ(S-R) edge reconstruction. Therefore, studies on GeSNR should be reconsidered. In this paper, we study the quantum confinement effects on the electronic properties of edge reconstructed monolayer GeS nanoribbon (GeSNR) by using first-principles calculations. As width of the nanoribbon increases from 10 to 41 Å, the band gap keeps indirect and linearly decreases from 1.57 to 0.87 eV. Robust spatial separation of valence band maximum and conduction band minimum exist in reconstructed GeSNR with width larger than 19 Å. Moreover, high carrier mobility is expected in the reconstructed GeSNR. Our results suggest that reconstructed GeS nanoribbon is an important candidate for optoelectronics and photocatalytic.