NOVELTY - Preparing copper tin sulfide (CTS) and copper zinc tin sulfide (CZTS) film, comprises: (a) preparing an ink comprising a copper source, a tin source, optionally, a zinc source, optionally, a chalcogen compound and optionally, a solvent; and (b) disposing the ink onto a substrate to form a coated substrate, provided that if there is no solvent, then at least one of the chalcogen compound and tin source is liquid at room temperature and if the copper source is copper sulfide or copper selenide and the tin source is tin sulfide or tin selenide, then the solvent is not hydrazine.    USE - The process is useful in preparing copper tin sulfide and copper zinc tin sulfide film, which is useful in producing a photovoltaic device (all claimed).    ADVANTAGE - The process provides CTS-selenium and CZTS-selenium at high purity and high yield.    DETAILED DESCRIPTION - Preparing copper tin sulfide (CTS) and copper zinc tin sulfide (CZTS) film, comprises: (a) preparing an ink comprising a copper source including copper complexes of nitrogen-, oxygen-, carbon-, sulfur-, or selenium-based organic ligands, copper sulfides and/or copper selenides, a tin source including tin complexes of nitrogen-, oxygen-, carbon-, sulfur- or selenium-based organic ligands, tin hydrides, tin sulfides and/or tin selenides, optionally, a zinc source including zinc complexes of nitrogen-, oxygen-, carbon-, sulfur-, or selenium-based organic ligands, zinc sulfides and/or zinc selenides, optionally, a chalcogen compound comprising elemental sulfur, elemental selenium, carbon disulfide, carbon diselenide, thiocarbonyl selenide, R1S-Z, R1Se-Z, R1S-SR1, R1Se-SeR1, R2C(S)S-Z, R2C(Se)Se-Z, R2C(Se)S-Z, R1C(O)S-Z and/or R1C(O)Se-Z, optionally, a solvent; and (b) disposing the ink onto a substrate to form a coated substrate, provided that: if there is no solvent, then at least one of the chalcogen compound and the tin source is a liquid at room temperature; and if the copper source is copper sulfide or copper selenide, and the tin source is tin sulfide or tin selenide, then the solvent is not hydrazine.    Z = H, NR44 or SiR53;    R1, R5 = hydrocarbyl, O-, N-, S-, halo- or tri(hydrocarbyl)silyl-substituted hydrocarbyl;    R2 = hydrocarbyl, O-, N-, S-, Se- halogen- or tri(hydrocarbyl)silyl-substituted hydrocarbyl or and O-, N-, S- or Se-based functional groups; and    R4 = H, O-, N-, S-, Se-, halo- or tri(hydrocarbyl)silyl-substituted hydrocarbyl or O-, N-, S-, and Se-based functional groups.