Patent ID: 7915521
Filing Date: 2011-03-29
Classification: B82Y,H01L,Y02E,Y10S

Abstract:
1. A photovoltaic device, comprising: a first electrode and a second electrode; a layer of a p-type semiconductor material disposed in a stack between the first electrode and the second electrode; a layer of an n-type semiconductor material disposed in a stack between the first electrode and the second electrode; a plurality of fence layers consisting essentially of a first semiconductor material disposed in a stack between the p-type and n-type semiconductor material layers; a plurality of layers consisting essentially of alternating layers of quantum dots of a second semiconductor material embedded between and in direct contact with a third semiconductor material that is different from the first semiconductor material, wherein the alternating layers are disposed in the stack between and in direct contact with a respective two of the plurality of fence layers, and wherein each quantum dot provides at least one quantum state at an energy between a conduction band edge and a valence band edge of the adjacent layers of the first semiconductor material; and wherein each quantum dot of the second semiconductor material and the third semiconductor material form a heterojunction having a type II band alignment.