Fabrication and characterization of CuInSe₂ thin film applicable for a solar energy light absorption material via a low temperature solid state reaction

The chalcopyrite CuInSe₂ thin film synthesized via a low temperature solid state reaction from CuSe and InSe powders was investigated using X-ray diffractomy (XRD), scanning electron microscope (SEM), energy dispersive spectrometer (EDS), transmission electron microscopy (TEM), and UV-vis absorption spectroscopy. CuSe and InSe phases react and directly transform into CuInSe₂ without the occurrence of any intermediate phase. The morphology of the newly formed CuInSe₂ crystalline was close to that of the CuSe reactant particle based on the TEM results, which indicate that the solid state reaction kinetics may be dominated by the In ³⁺ ions diffusion. The CuInSe₂ thin film prepared from the solid state reaction did not use the selenide process; its band gap might reach 1.06 eV, which is competent and suitable to be used for a thin film solar cell light absorption layer.