Experimental And Theoreticalinvestigations On Electronicstructure And Optical Of CuIn_0.75Ga_0.25(Se_1-y,S_y)₂Thin Films

The structural,optical and electric properties of CuIn0.75Ga0.25(Se1-y, Sy)2thin films were caculated by Material Studio5.5software based on dengsity functional theory and generalizaed approximation. The proportion of S/(Se+S)was25%,50%and75%, respectively. The results show that CIGSS thin films are direct band-gap semiconductors.CIGSS thin films of three different S content were deposited on soda lime glass substrates by pulsed laser deposition (PLD) method. The components of thin film were detected by energy dispersive spectroscopy (EDS). The optical properties of the films were analyzed by Uv-vis spectrophotometer. The surface morphology of the films were scanned by scanning electron microscopy (SEM). The electrical properties of the films were tested by Hall effect measurement system. The results show that CIGSS thin films of P-type prepared by the above methods have good crystallinity. When S/(Se+S) is75%, CIGSS thin film prepared by experiments behaves excellent structural, optical and electric properties, and the optical bandgap, carrier concentration, mobility and Hall coefficient of the film is1.85eV,4.740×1017cm-3,3.236Ωcm,13.2cm2V-1S-1and4.187×102cm3C-1,respectively.XRD patterns, absorption coefficient, the changs of band-gap and resistivity changes of three CIGSS films have a very good agreement in theory and experiment. As the S content increases, the band gap of CIGSS thin film increases, however, absorption coefficient and resistivity are reduced.