Stress affects the electronic transition and effectively regulates the optical properties of SnS2

SnS2 is a IV-VI group semiconductors, and has excellent photoelectronic properties, but the properties are significantly affected by stress. So, the properties and influence mechanism are studied using first principles method. The band gap of SnS2 shows three changes points with stress, which occurs at 1.0 GPa, 7.0 GPa and 8.0 GPa, respectively. The reason is that the electrons of Sn-5 s, Sn-5p and S-3p are sensitive differently to stress, the electrons are easy to be excited, and the electronic structure and optical properties are affected. The epsilon 1 and eta of SnS2 show three different variation rules, which are similar to the variation of the band gap, and the first peak of epsilon 1 increases with the increase of stress. epsilon 2, the edge of absorption and k are move to the direction of low energy with the increase of stress. It is means that stress can effectively regulate the electronic structure of SnS2 and improve the utilization of light.