First-principles calculation of electronic structure and optical properties of Cu2ZnSnO2S2

With the application of PBE plane wave ultra-soft pseudo-potential technology under the generalized gradient approximation(GGA) based upon the density function theory(DFT), the EV curve, enthalpy-pressure diagram, elasticity coefficient, energy band, state density, absorption coefficient, complex dielectric function, complex refractive index, reflectance, complex conductivity and energy loss function as a function of photon energy of the following four material structures, Cu₂ZnSnO₂S₂W-KS(Wurtzite-Kesterite), W-ST(Wurtzite-Stannite) and KS(Kesterite), ST(Stannite) are calculated and generated respectively, and these factors of each strictures are systematically compared. The results show that Cu₂ZnSnO₂S₂WKS is a direct bandgap semiconductor material. From the EV curve and the enthalpy-pressure diagram, it is known that the KS structure is more stable than the other three structures.