Tuning of optical performance of CrS2 monolayer using strain engineering

Abstract

In the present manuscript, the compressive and tensile strain in both uniaxial and biaxial directions are used to investigate the electronic and optical properties of CrS2 monolayer. It is revealed that both types of strain have a significant impact on the bandgap. For tensile strain, the value of Eg keeps decreasing but for compressive strain, the bandgap value first rises to 1.196 eV at 8% of uniaxial strain and then subsequently falls to 1.132 eV at 12% strain. The value of Eg in the biaxial case reaches to 1.75 eV at 6% compressive strain, and subsequently decreases to 0.60 eV at 12% compressive strain. The value of Eg for biaxial tensile strain continues to decrease and reached to 0.11 eV at 12% strain. The value of dielectric function i.e., ε2(ω) changes from 2.97 to 1.82 and then to 1.95 under 8% and 12% uniaxial compressive strain. ε2(ω) also changes from 2.97 to 2.52 and then to 3.30 under 4% and 12% biaxial compressive strain, respectively. A blue as well as a red shift in the absorption edge under compressive and tensile strains, respectively are observed. Our results imply that strain can be a useful tool for altering the optoelectronic properties of CrS2 monolayer.