A solar cell stack, having a first semiconductor solar cell having a p-n junction made of a first material with a first lattice constant, and a second semiconductor solar cell having a p-n junction made of a second material with a second lattice constant, and the first lattice constant being at least 0.008 Å smaller than the second lattice constant, and a metamorphic buffer, the metamorphic buffer being formed between the first semiconductor solar cell and the second semiconductor solar cell, and the metamorphic buffer including a series of three layers, and the lattice constant increasing in a series in the direction of the semiconductor solar cell, and the lattice constants of the layers of the metamorphic buffer being bigger than the first lattice constant, two layers of the buffer having a doping, and the difference in the dopant concentration between the two layers being greater than 4E17 cm.sup.−3.

A photovoltaic module comprises one or more spectrum splitting devices disposed adjacent a first side of the photovoltaic module; and a plurality of photovoltaic cells disposed adjacent a second side of the photovoltaic module opposite the first side and such that the photovoltaic cells are spaced from the one or more spectrum splitting devices, wherein at least one of the photovoltaic cells comprise a bifacial photovoltaic cell, wherein the one or more spectrum splitting devices are configured to selectively direct incident energy to one or more of the photovoltaic cells, and wherein a spatial configuration of the one or more spectrum splitting devices and the plurality of photovoltaic cells are configured based on an optimization parameter.

A photovoltaic module comprises one or more spectrum splitting devices disposed adjacent a first side of the photovoltaic module; and a plurality of photovoltaic cells disposed adjacent a second side of the photovoltaic module opposite the first side and such that the photovoltaic cells are spaced from the one or more spectrum splitting devices, wherein at least one of the photovoltaic cells comprise a bifacial photovoltaic cell, wherein the one or more spectrum splitting devices are configured to selectively direct incident energy to one or more of the photovoltaic cells, and wherein a spatial configuration of the one or more spectrum splitting devices and the plurality of photovoltaic cells are configured based on an optimization parameter.

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 power transmission system including a light output apparatus and a light receiving apparatus is provided. The light output apparatus includes a plurality of light sources having different wavelengths, and a light output control unit configured to control light outputs of the plurality of light sources, and the light receiving apparatus includes a photoelectric conversion element configured to absorb light beams emitted from the plurality of light sources, and convert the absorbed light beams into electrical power. The light output control unit individually sets each of the light outputs of the plurality of light sources.

A method of fabricating four junction solar cell wherein the selection of the composition of the subcells and their band gaps maximizes the efficiency at high temperature (in the range of 50 to 100 degrees Centigrade) in deployment in space at a specific predetermined time after initial deployment (referred to as the beginning of life or BOL), such predetermined time being referred to as the end-of-life (EOL), and being at least five years after the BOL, such selection being designed not to maximize the efficiency at BOL but to increase the solar cell efficiency at the EOL while disregarding the soar cell efficiency achieved at the BOL, such that the solar cell efficiency designed at the BOL is less than the solar cell efficiency at the BOL that would be achieved if the selection were designed to maximize the solar cell efficiency at the BOL.

A method of fabricating four junction solar cell wherein the selection of the composition of the subcells and their band gaps maximizes the efficiency at high temperature (in the range of 50 to 100 degrees Centigrade) in deployment in space at a specific predetermined time after initial deployment (referred to as the beginning of life or BOL), such predetermined time being referred to as the end-of-life (EOL), and being at least five years after the BOL, such selection being designed not to maximize the efficiency at BOL but to increase the solar cell efficiency at the EOL while disregarding the soar cell efficiency achieved at the BOL, such that the solar cell efficiency designed at the BOL is less than the solar cell efficiency at the BOL that would be achieved if the selection were designed to maximize the solar cell efficiency at the BOL.

Systems and methods of three-terminal tandem solar cells are described. Three-terminal metal electrodes can be formed to contact subcells of the tandem solar cell. The three-terminal tandem cell can improve the device efficiency to at least 30%.

Semiconductor devices comprising a semiconductor edge filter, a first light absorbing region overlying the semiconductor edge filter and a second light absorbing region underlying the semiconductor edge filter are disclosed. The semiconductor edge filter has a high reflectivity over a first wavelength range absorbed by the overlying light absorbing region and a high transmission over a second wavelength range absorbed by the underlying light absorbing region.

A beta-voltaic device made up of silica covered scintillating particles incorporated within an isotope absorbing layer to produce an improved power source. Lost beta particles are converted to UV light which is also converted to power in a beta-voltaic converter. The addition of the scintillating particles effectively increases the power efficiency of a BV device while maintaining the slim profile and smaller size of the power source. This arrangement makes possible implementation in space, defense, intelligence, medical implants, marine biology and other applications.