Characterization of structure and physical properties of CuInSe2 films prepared from chlorides under different conditions

Abstract

CuInSe2 films were prepared by spin-coating and chemical co-reduction method using chlorides and SeO2 as raw materials. The effects of different experimental conditions on the product films were investigated systematically, including on phase formation, crystallization, surface morphology and electrical conductivity of CuInSe2 films. And the reaction mechanism of CuInSe2 synthesis was analyzed. Experimental results show that, for the CuInSe2 film samples prepared with deionized water or ethanol as a solvent, at the same experimental temperatures of 180 °C, 200° C and 220 °C, the longer the reaction time, the better the crystallization of the film. While the X-ray diffraction (XRD) intensity of the film sample with 80 h reaction decreased, and the composition analysis by energy spectrum analyzer (EDS) proves that the sample contains three elements of Cu, In and Se. Increasing the reaction number is beneficial to the crystallization of the film sample, which makes the film more dense with higher conductivity. The resistivities of the CuInSe2 films prepared with different solvents show that the CuInSe2 film prepared with deionized water as a solvent has better conductivity. The CuInSe2 film after removing the impurity phase NaCl by soaking has lower resistivity and better conductivity. Keywords: Photoelectric film, Co-reduction, Spin-coating, Resistivity, CuInSe2