A multi junction laminated laser photovoltaic cell includes a cell unit laminated body and upper and lower electrodes electrically connected with the bottom and top of the cell unit laminated body, respectively, wherein the cell unit laminated body includes more than 6 laminated PN-junction subcells, adjacent two subcells are connected in series via tunnel junctions, wherein each PN-junction subcell uses a semiconductor single crystal material with a specific band gap as the absorption layer, the multiple subcells at least have two different band gaps, and the band gaps of the subcells are arranged in such an order that they decrease successively from the light incidence side to other side of the photovoltaic cell.

A multi junction laminated laser photovoltaic cell includes a cell unit laminated body and upper and lower electrodes electrically connected with the bottom and top of the cell unit laminated body, respectively, wherein the cell unit laminated body includes more than 6 laminated PN-junction subcells, adjacent two subcells are connected in series via tunnel junctions, wherein each PN-junction subcell uses a semiconductor single crystal material with a specific band gap as the absorption layer, the multiple subcells at least have two different band gaps, and the band gaps of the subcells are arranged in such an order that they decrease successively from the light incidence side to other side of the photovoltaic cell.

A photovoltaic device including a photovoltaic cell and method of use is disclosed. The photovoltaic cell includes at least a first photovoltaic layer and a second photovoltaic layer arranged in a stack. The first photovoltaic layer has a first thickness and receives light at its top surface. A second photovoltaic layer has a second thickness and is disposed beneath the first photovoltaic layer and receives light passing through the first photovoltaic layer. The first thickness and the second thickness are selected so that a first light absorption at the first photovoltaic layer is equal to a second light absorption at the second photovoltaic layer. The photovoltaic cell is irradiated at its top surface with monochromatic light to generate a current.

A photovoltaic device including a photovoltaic cell and method of use is disclosed. The photovoltaic cell includes at least a first photovoltaic layer and a second photovoltaic layer arranged in a stack. The first photovoltaic layer has a first thickness and receives light at its top surface. A second photovoltaic layer has a second thickness and is disposed beneath the first photovoltaic layer and receives light passing through the first photovoltaic layer. The first thickness and the second thickness are selected so that a first light absorption at the first photovoltaic layer is equal to a second light absorption at the second photovoltaic layer. The photovoltaic cell is irradiated at its top surface with monochromatic light to generate a current.

An InGaN solar photovoltaic device includes a base band, a light absorption layer, an n-type ZnO electron transport layer, and a p-type InN hole transport layer, the p-type InN hole transport layer is on a front side of the light absorption layer, and the base band and the n-type ZnO electron transport layer are on a back side of the light absorption layer, wherein the light absorption layer includes a p-type In.sub.xGa.sub.1-XN layer and an n-type In.sub.yGa.sub.1-yN layer which are superposed, where 0.2<x<0.4 and 0.2<y<0.4, and the p-type In.sub.xGa.sub.1-XN layer and the n-type In.sub.yGa.sub.1-yN layer are doped with Si and Mg. The InGaN solar photovoltaic device with a flexible multi-layer structure features high in energy conversion efficiency, low in cost, simple in manufacturing, and easy to implement, and thus has a broad prospect in application.

An InGaN solar photovoltaic device includes a base band, a light absorption layer, an n-type ZnO electron transport layer, and a p-type InN hole transport layer, the p-type InN hole transport layer is on a front side of the light absorption layer, and the base band and the n-type ZnO electron transport layer are on a back side of the light absorption layer, wherein the light absorption layer includes a p-type In.sub.xGa.sub.1-XN layer and an n-type In.sub.yGa.sub.1-yN layer which are superposed, where 0.2<x<0.4 and 0.2<y<0.4, and the p-type In.sub.xGa.sub.1-XN layer and the n-type In.sub.yGa.sub.1-yN layer are doped with Si and Mg. The InGaN solar photovoltaic device with a flexible multi-layer structure features high in energy conversion efficiency, low in cost, simple in manufacturing, and easy to implement, and thus has a broad prospect in application.

A multijunction solar cell including an upper first solar subcell having a first band gap and positioned for receiving an incoming light beam; a second solar subcell disposed below and adjacent to and lattice matched with said upper first solar subcell, and having a second band gap smaller than said first band gap; wherein the upper first solar subcell covers less than the entire upper surface of the second solar subcell, leaving an exposed portion of the second solar subcell around the periphery of the multijunction solar sell that lies in the path of the incoming light beam.

A multijunction solar cell including an upper first solar subcell having a first band gap and positioned for receiving an incoming light beam; a second solar subcell disposed below and adjacent to and lattice matched with said upper first solar subcell, and having a second band gap smaller than said first band gap; wherein the upper first solar subcell covers less than the entire upper surface of the second solar subcell, leaving an exposed portion of the second solar subcell around the periphery of the multijunction solar sell that lies in the path of the incoming light beam.

An assembly for optical to electrical power conversion including a photodiode assembly having a substrate layer and an internal side, an antireflective layer, a heterojunction buffer layer adjacent the internal side; an active area positioned adjacent the heterojunction buffer layer, a plurality of n+ electrode regions and p+ electrode regions positioned adjacent the active area, and back-contacts configured to align with the n+ and p+ electrode regions. The active area converts photons from incoming light into liberated electron hole pairs. The heterojunction buffer layer prevents electrons and holes of the liberated electron hole pairs from moving toward the substrate layer. The plurality of electrode regions are configured in an alternating pattern with gaps between each n+ and p+ electrode region. The electrode regions receive and generate electrical current from migration of the electrons and the holes, provide electrical pathways for the electrical current, and provide thermal pathways to dissipate heat.

A multijunction solar cell including an upper first solar subcell having a first band gap and positioned for receiving an incoming light beam; a second solar subcell disposed below and adjacent to and lattice matched with said upper first solar subcell, and having a second band gap smaller than said first band gap; wherein at least one of the solar subcells has a graded band gap throughout the thickness of at least a portion of the active layer.