A photovoltaic device is provided that includes a first electrode layer and a second electrode layer; and a waveguiding structure disposed between the first electrode layer and the second electrode layer which includes an active layer adapted to convert photons transmitted to the active layer to electrons and holes. The waveguiding structure further includes a first layer adjacent the first electrode layer that includes a hole-conducting material having a first index of refraction, and a second layer including an electron-conducting material having a second index of refraction, wherein the active layer is disposed therebetween. The active layer has an index of refraction that is less than each of the first index of refraction and the second index of refraction and a thickness. The waveguiding structure is characterized by guided modes adapted for optically confining the photons within the active layer.
STATEMENT OF GOVERNMENT RIGHTS
 This invention was made with Government support under contract number DE-AC02-98CH10886, awarded by the U.S. Department of Energy. The Government has certain rights in the invention.