Synthesis and characterization of CuInSe₂ thin film via a low temperature solid state reaction from CuSe and InSe powders

The hexagonal CuInSe₂ thinfilm was synthesized via a low temperature solid state reaction from CuSe and InSe powders. CuSe and InSe phases react and directly transform into CuInSe₂ without the occurrence of any intermediate phase and the morphology of the newly formed CuInSe₂ crystalline was close to that of the CuSe reactant particle based on the SEM results, which indicated that the solid state reaction kinetics may be dominated by the In³⁺ ions diffusion. The CuInSe₂ thin film were characterized using X-ray powder diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and transmission electron microscopy (TEM). The optical properties of the CuInSe₂ thin film were also recorded by UV-vis absorption spectroscopy. The CuInSe ₂ thin film prepare from the solid state reaction did not using the selenide process and its band gap was 1.06 eV which demonstrates that it is suitable for use in a thin film solar cell light absorption layer.