NOVELTY - The method comprises providing a stable colloidal suspension of metal surface-charged nanoparticles in a non-aqueous solvent, where the nanoparticles comprising copper(Cu) and elements either Groups IB, IIIA and optionally Group VIA or Groups IB, IIB and/or IVA and optionally Group VIA; preparing the colloidal suspension of a mixture of the nanoparticles in a liquid medium; submerging a substrate (61) and a counter electrode into the colloidal suspension; and depositing the mixture of nanoparticles onto the substrate to form a thin film photovoltaic absorber layer (63).    USE - The method is useful for fabricating a conformal metal chalcogenide thin film photovoltaic absorber layer on a surface of a complexly shaped object, where the photovoltaic absorber layer is useful in a multilayer photovoltaic device (claimed) including solar cell and solar panel.    ADVANTAGE - The method is capable of fabricating the thin film photovoltaic absorber layer in a rapid, a simple and an economical manner with desired crystal structure and improved packing density, and provides easy controllability of the chemical composition of the nanoparticles thus enhancing energy conversion efficiency of the solar cell.    DETAILED DESCRIPTION - The method comprises providing a stable colloidal suspension of metal surface-charged nanoparticles in a non-aqueous solvent, where the nanoparticles comprising copper(Cu) and elements either Groups IB, IIIA and optionally Group VIA or Groups IB, IIB and/or IVA and optionally Group VIA; preparing the colloidal suspension of a mixture of the nanoparticles in a liquid medium; submerging a substrate (61) and a counter electrode into the colloidal suspension; depositing the mixture of nanoparticles onto the substrate to form a thin film photovoltaic absorber layer (63) by electrophoretic deposition; forming the nanoparticles by a physical breakdown of a bulk material, in a vacuum, a gas medium or the liquid medium; subjecting the thin film photovoltaic absorber layer to chalcogenization and annealing; placing the counter electrode and a surface of a complexly shaped object into a suspension of metal surface-charged nanoparticles; forming a metal thin film on the surface of the complexly shaped object using the electrophoretic deposition method; heating the metal thin film in a presence of a chalcogen to form a metal chalcogenide thin film on the surface of the complexly shaped object; forming a buffer layer adjacent to the metal chalcogenide thin film by a chemical bath deposition of cadmium sulfide; forming an insulating layer adjacent to a side of the buffer layer opposite to the metal chalcogenide thin film layer by a chemical vapor deposition of zinc oxide; and forming a transparent conductive contact adjacent to a side of the insulating layer opposite to the buffer layer by a chemical vapor deposition of an aluminum doped zinc oxide. An atomic ratio between Cu and group IIIA and optional group VIA elements and between Cu and group IIB and group IVA elements and optional group VIA elements are predetermined that is 25%:25%:15-50% respectively. The step of providing nanoparticles comprises providing nanoparticles consisting of copper (Cu), indium (In), aluminum (Al), gallium (Ga) selenium (Se) and sulfur (S), zinc (Zn), tin (Sn), binary or ternary alloys of Cu-In, Cu-Ga, In-Ga, (Al, Ga)-In, Cu-(Al, In, Ga), Cu-Zn, Cu-Sn, and Zn-Sn and from binary, ternary, or quaternary compounds of Cu-(S, Se), (Al, Ga, In)-(S, Se), Zn-(S, Se), Sn-(S, Se), Cu-(Al, Ga, In)-(S, Se) and Cu-Zn-Sn-(S, Se). The nanoparticles: have an identical atomic ratio between the elements as the bulk material; are formed by a pulsed laser ablation of the bulk material, thermal evaporation of the bulk material, arc discharge of the bulk material, plasma evaporation of the bulk material, mechanical ball milling of the bulk material, laser pyrolysis of the bulk material and evaporative-condensation of the bulk material or explosion of wires formed from the bulk material; and have shapes of a nanosphere, a nanorod, a nanowire, a nanocube, a nanoflower and/or a nanoflake and a dimension of less than or equal to 500 nm. The liquid medium comprises water and water-miscible organic solvent having 1-6C and a dielectric constant of greater than 20. The step of preparing the colloidal suspension a mixture of the nanoparticles in a liquid medium comprises adding an acid, a base, an electrolyte, a surfactant and/or a dispersant to the liquid medium. The substrate includes a sheet of glass with a conductive coating on it and a polymeric sheet with a conductive coating on it. The counter electrode is in the form of a planar sheet, a mesh, or a sheet with hollow center areas. The counter electrode has a pre-determined shape determined by a surface topography of a semi-electrically conductive surface of a complexly shaped object and provides a constant-electric field constraint between the counter electrode and the surface of the complexly shaped object. The atomic ratio of Cu: (Ga+In) is 0.7-1.0. The atomic ratio of Ga: (Ga+In) is 0.1-0.5. The step of placing the counter electrode and the surface of the complexly shaped object into the suspension comprises applying a voltage bias of 25-5000V between the counter electrode and the surface to cause the electrophoretic deposition. The metal chalcogenide thin film has a thickness of 100 nanometers to 10 micrometers. The heating step comprises depositing the chalcogen onto the metal thin film, heating the thin film to a temperature of 200-700 degrees C, and causing the chalcogen to diffuse into the thin film. An INDEPENDENT CLAIM is included for a multilayer photovoltaic device.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic view of a photovoltaic cell.    Substrate (61)    Back electrode (62)    Photovoltaic absorber layer (63)    Window layer (64)    Transparent electrode. (65)