Method for producing copper-indium-selenium thin-film solar cell wealthy-indium optical absorption layer

The invention provides a method of preparing an In-enriched light absorption layer for a CuInSe2 thin-film solar battery, belonging to the preparation of CuInSe2 semiconductor thin films. The method adopts coating-sintering process, and uses Cu-In alloy, Cu-In alloy and Se powder as raw material. The method comprises mixing Cu-In alloy, Cu-In alloy and Se powder with a molar ratio of 1:(1.1-1.25):2:(2-2.2), ball milling the mixture for 36-72 hr to form a black precursor slurry; coating the slurry on a molybdenum foil substrate or a titanium foil substrate to form a precursor thin-film, and drying at low temperature; densifying the precursor thin-film by exerting 10-300 MPa pressure, and subjecting the precursor thin-film to heat treatment under H2 atmosphere, N2 atmosphere or vacuum. The method can accurately control the chemical composition in the precursor thin-film, can ensure the preparation of the In-enriched CuInSe2 semiconductor thin-film solar battery, and is more suitable for forming the absorption layer with uniform composition, compact structure, and flat surface. And, the sintering process is performed under innoxious atmosphere, so as to be safe and practice in operation.