Method for preparing thin-film solar cell p-n junction

The invention discloses a method for preparing a thin-film solar cell p-n junction. The method includes the following steps of cleaning a substrate, drying the substrate by nitrogen, placing the substrate on a substrate table in a cavity of a plasma chemical vapor deposition system, placing a raw material containing tins and a raw material containing sulfurs into two crucibles respectively, placing the two crucibles into a raw material evaporation device of the plasma chemical vapor deposition system, closing the cavity, vacuumpumping, feeding argon to produce an argon plasma, subjecting the cavity of the plasma chemical vapor deposition system and the substrate in the cavity to a cleaning treatment by the argon plasma, heating the substrate, preparing an n type tin sulfur film and a p type tin sulfur film on the substrate surface which is cleaned, subjecting the prepared n type and the p type tin sulfur films to a vacuum annealing in the cavity of the plasma chemical vapor deposition system, and cooling the