A light harvesting supercapacitor and a method of preparing the light harvesting supercapacitor are disclosed. The light harvesting supercapacitor includes a transparent substrate, an active layer including TiO2 nanoparticles and polyaniline (PANI) nanoparticles disposed on the transparent substrate, an electrolyte layer including a solid separator and poly(2-acrylamido-2-methyl-1-propanesulfonic acid) disposed on the active layer, a carbon electrode disposed on the electrolyte layer; and a metal layer disposed on the activated carbon electrode. The method of preparing the light harvesting supercapacitor involves pulsed laser ablation in a liquid of bulk PANI to form the PANI nanoparticles. The light harvesting supercapacitor can be used in a photovoltaic device.