CIGS-based solar cells prepared from electrodeposited stacked Cu/In/Ga layers

Previously, we reported 15.4%-efficient copper indium gallium diselenide (CIGS)-based photovoltaic devices from electrodeposited precursor films in which the final film composition was adjusted using the physical vapor deposition (PVD) method. At present, we are fabricating CIGS-based solar cells directly from electrodeposited precursor films, eliminating the expensive PVD step. Electrodeposited CIGS absorber layers are fabricated from a stacked Cu/In/Ga layers. All films are electrodeposited from an aqueous-based solution at room temperature in a two-electrode cell configuration, with platinum gauze as the counter electrode and a glass substrate as the working electrode. The substrate is DC-sputtered with about 1 μm of Mo. The electrodeposited films are selenized at high temperature (∼550 °C) to obtain 11.7%-efficient device.