NOVELTY - Method of depositing a kesterite film (I) comprising a metal compound, comprises: contacting hydrazine, a source of copper (Cu), a source of tin (Sn), a source of at least one of sulfur (S) and selenium (Se), and a source of zinc (Zn) forming a dispersion comprising Zn-containing solid particles; applying the dispersion onto a substrate to form a thin layer; and annealing at a temperature, pressure, and length of time sufficient to form (I).    USE - The method is useful for depositing a kesterite film on a substrate (metal foil, glass, ceramics, aluminum foil coated with a layer of molybdenum and/or a polymer), which is useful in a photovoltaic device (all claimed). The film on substrate is useful as optical, electrical, anti-friction, bactericidal, catalytic, photo-catalytic, electromagnetic shielding, wear-resistance, and diffusion barrier.    ADVANTAGE - The method forms large-grained films with good electrical characteristics. The process enables the incorporation of select metal chalcogenide anions directly in solution, and particle-based deposition, which allows the incorporation of additional otherwise insoluble components. The method enables the high-throughput low-capital-cost fabrication of thin films of different semiconductor materials, ranging from new chalcogenide-based photovoltaic absorbers to a broader range of materials employed in the optical, electronic and other semiconductor industries. The photovoltaic devices (containing (I)) exhibit high efficiency. The process is possible to deposit highly pure semiconductor layers by printing techniques without the necessity to use organic enhancers. The process provides effective binding media surrounding the particles while the particles have stress-relief and crack-deflection effect permitting the deposition of thicker films in single coating.    DETAILED DESCRIPTION - Method of depositing a kesterite film (I) comprising a metal compound of formula (Cu2-xZn1+ySn(S1-zSez)4+g), comprises: contacting hydrazine, a source of copper (Cu), a source of tin (Sn), a source of at least one of sulfur (S) and selenium (Se), and a source of zinc (Zn) forming a dispersion comprising Zn-containing solid particles; applying the dispersion onto a substrate to form a thin layer; and annealing at a temperature, pressure, and length of time sufficient to form (I).    x-z = 0-1 (preferably x and y are 0-0.5); and    q = -1 to 1 (preferably -0.5 to 0.5).    INDEPENDENT CLAIMS are included for:    (1) a composition comprising a dispersion of Zn-containing solid particles formed from hydrazine, a source of Cu, a source of Sn, a source of Zn, and a source of at least one of S and Se, which when annealed, forms (I); and    (2) a photovoltaic device, comprising: a top electrode having transparent conductive material, an n-type semiconducting layer, (I) on the substrate formed by the method, and a substrate having an electrically conductive surface.