NOVELTY - The method involves depositing silica or silica-coated polystyrene nanospheres onto a substrate (104). The silica or silica-coated polystyrene nanospheres and the substrate are etched (108) to form nanocone projections on a side of the substrate. A transparent conducting oxide film is deposited (110) onto the substrate on top of the nanocone projections. Photovoltaic materials are deposited (114) onto the transparent conducting oxide film to form a thin film solar cell. The substrate is made of glass, quartz or fused silica material.    USE - Method for fabricating a nanotextured conducting panel in a thin film solar cell (claimed).    ADVANTAGE - The method enables fabricating nanotextures e.g. nanopillars and nanocones, on transparent conductive substrates optimized so as to reduce reflection and increase light-trapping efficiency in thin absorber layers. The method enables forming nanopillars and nanocones with high aspect ratios on the substrate in a highly controlled manner so as to achieve addressing of optimal parameters for light absorption in the thin film solar cell by effectively grading an index of refraction between the substrate and an absorber using sub-wavelength texturing, and providing maximal coupling to guided modes in an thin-film absorber layer using textures with optimized period, height and fill factor.    DETAILED DESCRIPTION - The photovoltaic materials are selected from one of thin-film amorphous, microcrystalline silicon and copper indium gallium selenide (CIGS). An INDEPENDENT CLAIM is also included for a thin film solar cell.    DESCRIPTION OF DRAWING(S) - The drawing shows a flow diagram illustrating a method for fabricating a nanotextured substrate.    Step for depositing silica or silica-coated polystyrene nanospheres onto substrate (104)    Step for etching silica or silica-coated polystyrene nanospheres and substrate to form nanocone projections on side of substrate (108)    Step for depositing transparent conducting oxide film onto substrate on top of nanocone projections (110)    Step for depositing photovoltaic materials onto transparent conducting oxide film to form thin film solar cell (114)    Step for depositing conductive contact layer on photovoltaic materials (118)