Abstract: A photovoltaic solar collector and concentrator apparatus consists of a solid, one-piece, sun light transmitting, non-imaging optical element coupled to a photovoltaic cell. The photovoltaic solar collector and concentrator has an entry surface including focusing elements and an opposed surface including uncoated reflector elements. The focused sun light is directed by the reflector elements via total internal reflection directly towards the photovoltaic cell without any reflection from the entry surface. An additional redirecting element based on total internal reflection and integral with the collector and concentrator optical element is used to couple the sunlight from the reflector elements to a photovoltaic cell positioned in plane parallel to the entry surface.

Abstract: A photovoltaic light guide solar concentration apparatus has a deflecting layer, a light-guide layer optically coupled to the deflecting layer, a secondary optic and a photovoltaic cell. The photovoltaic concentration apparatus has a central optical axis that, in operation, is parallel to incident sunlight. A deflecting layer includes a plurality of focusing elements symmetrically arranged with respect to the central optical axis. The light-guide layer is optically coupled to the plurality of focusing elements of the deflecting layer. The light-guide layer has a reflective surface and a plurality of opposite facets symmetrically arranged with respect to the central axis and focused sunlight from the deflection layer enters the light-guide layer and is directed and trapped by the reflective surface and the opposite facets and guided inside the light-guide layer towards an exit aperture through total internal reflections.

Abstract: A composite material is described. The composite material comprises semiconductor nanocrystals, and organic molecules that passivate the surfaces of the semiconductor nanocrystals. One or more properties of the organic molecules facilitate the transfer of charge between the semiconductor nanocrystals. A semiconductor material is described that comprises p-type semiconductor material including semiconductor nanocrystals. At least one property of the semiconductor material results in a mobility of electrons in the semiconductor material being greater than or equal to a mobility of holes. A semiconductor material is described that comprises n-type semiconductor material including semiconductor nanocrystals. At least one property of the semiconductor material results in a mobility of holes in the semiconductor material being greater than or equal to a mobility of electrons.

Abstract: A composite material is described. The composite material comprises semiconductor nanocrystals, and organic molecules that passivate the surfaces of the semiconductor nanocrystals. One or more properties of the organic molecules facilitate the transfer of charge between the semiconductor nanocrystals. A semiconductor material is described that comprises p-type semiconductor material including semiconductor nanocrystals. At least one property of the semiconductor material results in a mobility of electrons in the semiconductor material being greater than or equal to a mobility of holes. A semiconductor material is described that comprises n-type semiconductor material including semiconductor nanocrystals. At least one property of the semiconductor material results in a mobility of holes in the semiconductor material being greater than or equal to a mobility of electrons.