First-Principles Studies Of Electronic Structures And Optical Properties Of CuInSe₂ Doped With Ga

The compound semiconductor copper-indium-diselenide is the basic material of absorbing layer of CuInSe2 thin film solar cells. The conversion efficiency of solar cells can be improved effectively by doping CuInSe2 thin films, and partial substitution of Ga for In in the CuInSe2 is the accustomed methods in experiment. In this article, the electronic structures and optical properties of Ga-doped tetragonal chalcopyrite CuInSe2 were calculated using full-potential linearized augmented plane wave method (FPLAPW) based on the density functional theory (DFT). At first, lattice parameters of doped and undoped CuInSe2 were optimized geometrically. On this basis, the total and partial density of states, band structures and absorption coefficients of doped and undoped Cu(In, Ga)Se2 were calculated and comparative analyzed, in the calcularions, the Ga doped concentrations were 1/8,1/4 and 1/2. Effect of Ga doping on crystal performance of CuInSe2 were discussed.