NOVELTY - The method comprises: forming (304) a dielectric layer on a substrate; forming (308) a solder layer on the dielectric layer; annealing (310) the solder layer to form uniformly distributed solder balls on the dielectric layer; etching (314) the substrate using the solder balls to protect portions of the substrate to form pillars in the substrate such that the pillars provide a radiation absorbing structure in the photovoltaic device; and wet etching (316) the pillars to form cone-shaped structures to be incorporated into the photovoltaic device.    USE - The method is useful for fabricating a photovoltaic device (claimed).    ADVANTAGE - The method is capable of fabricating economically photovoltaic device with improved absorption of incident radiation, less reflectivity and increased carrier collection efficiency using cone-shaped pillar.    DETAILED DESCRIPTION - The method comprises: forming (304) a dielectric layer on a substrate; forming (308) a solder layer on the dielectric layer; annealing (310) the solder layer to form uniformly distributed solder balls on the dielectric layer; etching (314) the substrate using the solder balls to protect portions of the substrate to form pillars in the substrate such that the pillars provide a radiation absorbing structure in the photovoltaic device; and wet etching (316) the pillars to form cone-shaped structures to be incorporated into the photovoltaic device. The method further comprises: forming electrode and a diode stack on the cone-shaped structures to provide an active layer for providing current flow responsive to incident radiation; and controlling dimensions and density of the pillars by adjusting the diblock copolymer composition. The solder layer has a thickness of 20-2000 nm. The step of annealing includes a rapid thermal annealing process. The step of etching the substrate includes performing a reactive ion etches such that black silicon is formed, and performing a reactive ion etches with tetrafluoromethane plasma. The diode stack is arranged between two electrodes, where one electrode is transparent and includes a p-doped layer, an intrinsic layer and an n-doped layer. An INDEPENDENT CLAIM is included for a photovoltaic cell.    DESCRIPTION OF DRAWING(S) - The figure shows a flow chart of a method for fabricating a photovoltaic device.    Forming dielectric layer (304)    Forming solder layer (308)    Annealing solder layer (310)    Etching substrate to form pillars (314)    Wet etching substrate to form cones . (316)