NOVELTY - Fabricating conformal metal chalcogenide thin film (105) photovoltaic absorber layer on surface of complexly shaped object involves: providing stable colloidal suspension of metal surface-charged nanoparticles in non-aqueous solvent; providing counter electrode for electrophoretic deposition of nanoparticles, where electrode have pre-determined shape; placing electrode and surface of object into suspension of metal surface-charged nanoparticles and using electrophoretic deposition forming metal thin film; and heating film in presence of chalcogen to form metal chalcogenide thin film.    USE - For fabricating a conformal metal chalcogenide thin film photovoltaic absorber layer on a surface of a complexly shaped object (claimed) such as car bodies.    ADVANTAGE - The method offers several unique advantages. The precursor is fluid, so deposition is conformal, which is unique to our method. The band gap can be graded by doing multiple depositions with nanoparticles of different compositions. The electrophoretic deposition is well established, and has been used to deposit primer layers on car bodies. The material usage is much more efficient in the current method compared to the conventional vacuum-based and other non-vacuum-based techniques. The method reduces the environmental footprint of the process of forming a photovoltaic absorber layer.    DETAILED DESCRIPTION - Fabricating a conformal metal chalcogenide thin film (105) photovoltaic absorber layer on a surface of a complexly shaped object, involves: a) providing a stable colloidal suspension of metal surface-charged nanoparticles in a non-aqueous solvent, where the nanoparticles comprises elements either from Groups IB, IIIA and optionally Group VIA or from Groups IB, IIB and/or IVA and optionally Group VIA; b) providing a counter electrode for electrophoretic deposition of the nanoparticles, the counter electrode having a pre-determined shape determined by a surface topography of a surface of a complexly shaped object and providing a substantially constant-electric field constraint between the counter electrode and the surface of the complexly shaped object, where the surface is semi-electrically conductive; c) placing the counter electrode and the surface of the complexly shaped object into the suspension of metal surface-charged nanoparticles and using electrophoretic deposition forming a metal thin film on the surface of the complexly shaped object; and d) heating the metal thin film in the presence of a chalcogen to form a metal chalcogenide thin film on the surface of the complexly shaped object.    DESCRIPTION OF DRAWING(S) - The figure shows a method for the preparation of a copper-indium-gallium-selenide (CIGS) solar cell.    Metal chalcogenide thin film (105)    Buffer layer (106)    Insulating layer (107)    Transparent conducting oxide layer (108)