The invention discloses a CIGS (
copper indium gallium selenium)
thin film solar cell and a preparation method thereof, and belongs to the technical field of the
solar cell. The
solar cell is formed by successively connecting a substrate, a
metal anode, a light
absorption layer, a buffer layer, a window layer, a transparent
electrode layer and a grid-shaped
metal cathode, wherein the light
absorption layer consists of at least two
layers of CIGS thin films of different energy gaps; and each CIGS single layer of the light adsorption layer is directly formed into the film by regulating the magnetron
sputtering pressure, the temperature range and the
power density, or a prefabricated layer is prepared by magnetron
sputtering; and then, the prefabricated layer is subjected to selenylation
processing to obtain the CIGS thin film at the temperature of 400-500DEG C under the protection of
argon or
nitrogen. Each single layer of CIGS thin film disclosed by the invention has different energy gaps, the shape of the energy band of the light
absorption layer can be regulated in a combined mode, the collection and
light spectrum response curve of a carrier can be both considered, and the
absorption efficiency of the light absorption layer is improved by 30-50%. The CIGS
thin film solar cell and the preparation method disclosed by the invention have the advantages of
high cell photoelectric conversion efficiency, simple technology, simple required equipment and easiness in realizing
mass production.