NOVELTY - Forming a photovoltaic absorber layer involves depositing a solution on a substrate (102) to form a precursor layer (106), where the solution contains at least one Group IB and/or IIIA hydroxide, at least one optional polar solvent, and at least one optional binder; and processing the precursor layer in at least one step, to form a photovoltaic absorber layer. The Group IB and/or IIIA hydroxide preferably comprise indium hydroxide, gallium hydroxide or indium-gallium hydroxide.    USE - For forming an absorber layer useful in photovoltaic device such as solar cell; and particularly useful for forming absorber layer made of copper-indium-gallium-selenide (CIGS), used in CIGS solar cell.    ADVANTAGE - The method forms photovoltaic absorber layer, which is applicable to any type of solar cell, irrespective of its rigidity/flexibility or the type of material used in the absorber layer. The method is adaptable for roll-to-roll and/or batch manufacturing processes. The method enables use of lower cost substrates in conjunction with non-vacuum deposition of photovoltaic absorber materials containing copper-indium-gallium-selenide (CIGS), to form photovoltaic absorber layer. Thus, the method decreases the cost associated with CIGS-based solar devices, increasing their market penetration and commercial adoption.    DETAILED DESCRIPTION - Forming a photovoltaic absorber layer involves depositing a solution on a substrate (102) to form a precursor layer (106), where the solution contains at least one Group IB and/or IIIA hydroxide, at least one optional polar solvent, and at least one optional binder; and processing the precursor layer in at least one step, to form a photovoltaic absorber layer. The Group IB and/or IIIA hydroxide preferably comprise indium hydroxide, gallium hydroxide or indium-gallium hydroxide. The binder is preferably an organic binder. The polar solvent is preferably an organic solvent. The photovoltaic absorber layer is preferably formed by processing the precursor layer into a solid film, and then thermally reacting the solid film in an atmosphere containing at least one Group VIA element. The method further involves annealing the photovoltaic absorber layer; and selenizing the annealed layer using selenium vapor in a non-vacuum atmosphere, to form thin film layer that includes at least one chalcogenide compound containing copper, indium, gallium and selenium.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic cross-sectional view of a fabrication step of a photovoltaic absorber layer/film.    Substrate (102)    Precursor layer (106)    Discrete layer containing an extra source of chalcogen. (107)