Electrodeposition of p+, p, i, n and n+-type copper indium gallium diselenide for development of multilayer thin film solar cells

Copper indium gallium diselenide (CuInGaSe2) layers with p+, p, i, n, and n+-type electrical conduction, as pre-determined, have been electrodeposited from aqueous solutions in the same bath. The photoelectrochemical cell (PEC) has been used as the key analytical tool to determine the electrical conduction type, and the corresponding stoichiometry of the layers was determined using X-ray fluorescence (XRF). A four-layer n-n-i-p solar cell structure was fabricated and a corresponding energy band diagram for the device was constructed. Current-voltage (I-V) and capacitance-voltage (C-V) measurements were carried out to assess the devices and these indicate encouraging characteristics enabling further development of multilayer thin film solar cells based on CuInGaSe2.