NOVELTY - The method involves forming an absorber layer on a molybdenum layer (202) of a solar cell base structure (300), where the molybdenum layer is located on a substrate (201), and the absorber layer comprises semiconductor chalcogenide material. The solar cell base structure is annealed and sulfurized by exposing an outer layer of the solar cell base structure to a plasma formed from gas including sulfur by positioning the solar cell base structure between radio frequency (RF) coils and activating the RF coils to form a region of plasma on the outer layer.    USE - Method for performing oxygen plasma annealing of a thin film preliminary solar cell structure.    ADVANTAGE - The method enables performing annealing of the solar cell base structure while exposing an upper surface of the solar cell base structure to plasma at lower temperature, so that delamination of layers in the solar cell base structure is decreased, bonds between layers of the subject area are strengthened, and damage resulting from high-temperature annealing is reduced, thus improving solar collection efficiency of the solar cell base structure and decreasing delamination of layers i.e. molybdenum disulfide layer, from a copper tin zinc sulfur layer, improving bonding of metal electrodes with the indium tin oxide layer, bonding of the indium tin oxide layer with a buffer layer i.e. cadmium sulfide layer, and bonding of the cadmium sulfide layer with a copper tin zinc sulfur absorber layer to lower series resistance of the solar cell device, increase a fill factor (FF), cure p-n junction defects of the cadmium sulfide layer with adjacent layers and improve short circuit current density.    DETAILED DESCRIPTION - The substrate is a glass substrate, metal substrate and plastic substrate. The method enables annealing the solar cell base cell structure resulting in a chalcogenide layer (207) comprising one of Copper-Indium-sulfur-Selenium and cupric indium gallium selenide, kesterite-Copper-Zinc-Iron-Tin-selenide, sulfur-gallium-selenide, gallium-Tellurium, gallium-Arsenic, Indium-sulfur-selenide, Indium-Tellurium, Tellurium-Phosporous, Cadmium-Tellurium, Cadmium-sulfur- selenide, Zinc-Tellurium, Lead-selenide-sulfur, Zinc-sulfur-selenide, Tungsten-sulfur-selenide, Bismuth Sulphide, Silver sulfide, Nickel sulfide, Zinc oxide, Cuprous Oxide, cupric oxide, Copper sulfide and ferric sulfide. The gas including sulfur is hydrogen sulfide. The method enables forming a transparent conductive oxide layer (210) on the buffer layer, where the TCO layer comprises an indium tin oxide layer and aluminum doped zinc oxide layer. An INDEPENDENT CLAIM is also included for a method for annealing an absorber layer.    DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional view of a solar cell structure.    Substrate (201)    Molybdenum layer (202)    Molybdenum disulfide layer (206)    Chalcogenide layer (207)    Cadmium sulfide layer (208)    Intrinsic zinc oxide layer (209)    TCO layer (210)    Solar cell base structure (300)