INFLUENCE OF CU/IN RATIOS AND THE GROWTH TEMPERATURE ON THE MICROSTRUCTURAL PARAMETERS OF SPRAYED CUINSE2 THIN FILMS

In this article, copper indium di-selenide at different ratios of Cu:In thin films have been grown on heated glass substrates using chemical spray pyrolysis. Characterizations and compositional analysis of CuInSe2 thin films were obtained by X-ray diffraction (XRD) and electron dispersion analysis (EDX). Microstructural parameters as a function of Cu/In ratio ranged from 0.9 to 1.1 and the growth temperature (Tsub) in the range of 548K to 623K have been study. Williamson-Hall method has been used to determine the microstructural parameters (crystallite size, microstrain and lattice parameters). X-ray diffraction study confirmed poly-crystalline CuInSe2 thin films with the hexagonal crystal structure having preferential growth along the <002> direction. At the Cu/In ratio increased, the crystallite size was found to be increased and decreased with the growth temperature. On the contrary, the microstrain values were decreasing with the growth temperature and Cu/In ratio were increasing. Also, the increasing of Cu/In ratio leads to improve the degree of crystallization and decrements of both, the lattice parameters and volume of unit cell. These results are very important in solar cell applications for high efficiency.