Theoretical Study On The Electronic And Optical Properties Of Strain-Tuned Cspb(I1-Xbrx)(3) And Cssn(I1-Xbrx)(3)

In this work, we investigate the electronic and optical properties of CsPb(I1-xBrx)(3) and CsSn(I1-xBrx)(3) by using density functional theory. We have proposed the method of strain modulation to efficiently tune the bandgap of CsPb(I1-xBrx)(3) and CsSn(I1-xBrx)(3) perovskites. Our calculations show that, the bandgap of CsPbI3 can be successfully tuned with the strain variation of -3% to 3%. Furthermore, the electronic structure changes of CsPb(I1-xBrx)(3) and CsSn(I1-xBrx)(3) with Br concentration, the higher the Br doping concentration, the higher will be the energy band value. We believe that the effective regulation of the energy bandgap can fulfill the requirements of a promising light-harvesting material.