Liquid CO2-based coating for dense CuInxGa1−xS2 film fabrication.

A liquid CO 2 ( l -CO 2 )–based coating technique is used for the pore-filling of a porous copper indium gallium sulfide (CuIn x Ga 1−x S 2 , CIGS) film synthesized by a solution-based method. In the l -CO 2 –based coating, copper and indium precursors dissolved in l -CO 2 are deposited on the porous copper indium gallium oxide film, followed by low-temperature sulfurization. After the high-temperature sulfurization of the deposited film with the l -CO 2 –based coating, a highly dense CIGS film with almost complete pore-filling is obtained. The use of an indium rich solution in l -CO 2 leads to the formation of near stoichiometric ratio of Cu:(In + Ga) that improves the pore filling behavior. [ABSTRACT FROM AUTHOR]