Non-monotonic pressure dependence of band gap in SnTe

The electronic properties of SnTe under pressure are studied using first-principles calculations. The results show that the band gap energy changes non-monotonically with pressure, gradually reducing to zero, then rising. It may be because with pressure the inertia of s state near the bottom of the conduction band is weakened, and the repulsion to p state is enhanced, which pushes the L6+ level down. The work demonstrates an approach for manipulating the electrical properties of SnTe, which is important for future applications based on SnTe.