Disclosed herein are large area, multi-layer solar devices comprising a substrate, an active area comprising at least one donor material and at least one acceptor material deposited on a surface of the substrate, wherein the donor and acceptor materials are comprised of organic molecules, and wherein particulates are removed from the surface of the substrate before deposition of the donor and acceptor materials. Particulates may be removed by exposing the surface of the substrate to a stream of at least one compound comprising one or more phases chosen from supercritical, gaseous, solid, and liquid phases. Also disclosed are methods of manufacturing photovoltaic devices comprising providing a substrate, cleaning a surface of the substrate by exposing the surface to a stream of at least one compound comprising one or more phases chosen from supercritical, gaseous, solid, and liquid phases, and depositing an organic active layer on the surface of the substrate.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
 This invention was made with Government support under DE-EE0005310 awarded by the Department of Energy and FA9550-10-1-0339 awarded by the Air Force Office of Scientific Research. The government has certain rights in the invention.