Blocking thin-film nonuniformities: Photovoltaic self-healing

Abstract

An approach is developed to block the effects of lateral nonuniformities in thin-film semiconductor structures. The nonuniformity modulates the surface photovoltage distribution. When exposed to light and immersed in a proper electrolyte, this distribution will generate laterally nonuniform electrochemical reactions. Such treatments result in a nonuniform interfacial layer that balances the original nonuniformity. This approach has been implemented for CdTe/CdS photovoltaic devices, in which it improved the device efficiency from 1%–3% to 11%–12%.