A solar cell optimized for performance at high radiation doses, wherein the solar cell includes: a sub-cell comprised of a base and an emitter; the base of the sub-cell has a thickness of about 2 to 3 m; the base of the sub-cell is doped at about 1e14 cm.sup.3 to 1e16 cm.sup.3; and a reflector is inserted behind the sub-cell to maximize current generated by the sub-cell.

A solar cell optimized for performance at high radiation doses, wherein the solar cell includes: a sub-cell comprised of a base and an emitter; the base of the sub-cell has a thickness of about 2 to 3 m; the base of the sub-cell is doped at about 1e14 cm.sup.3 to 1e16 cm.sup.3; and a reflector is inserted behind the sub-cell to maximize current generated by the sub-cell.

A method of coordinating wireless power transfer and data communication between a transmitter and a receiver comprising recognizing at the receiver that an energy store electrically coupled to the receiver requires an electrical charge, emitting from the receiver a beacon signal to the transmitter, the beacon signal including information about the receiver and a state of charge of the energy store, recognizing at the receiver first and second localization signals from the transmitter, establishing low-power and high-power laser beam connections between the receiver and the transmitter in response to the localization signals, and communicating further information via the low-power beam on a periodic basis while optical power is being transferred via the high-power beam. The low-power beam connection includes further information about the receiver and the state of charge of the energy store. Optical power is transferred from the transmitter to the receiver via the high-power beam.

According to an aspect of the present invention, there is provided a compound semiconductor solar cell, comprising: a light absorbing layer comprising a compound semiconductor; a first electrode positioned on a front surface of the light absorption layer; a first contact layer positioned between the light absorbing layer and the first electrode; a second electrode positioned on a rear surface of the light absorbing layer and having a sheet shape; and a second contact layer positioned between the light absorbing layer and the second electrode. The second contact layer is partially formed on the rear surface of the light absorbing layer on the projection surface, and the second electrode includes a first portion in direct contact with the second contact layer and a second portion located between the first portions.

According to an aspect of the present invention, there is provided a compound semiconductor solar cell, comprising: a light absorbing layer comprising a compound semiconductor; a first electrode positioned on a front surface of the light absorption layer; a first contact layer positioned between the light absorbing layer and the first electrode; a second electrode positioned on a rear surface of the light absorbing layer and having a sheet shape; and a second contact layer positioned between the light absorbing layer and the second electrode. The second contact layer is partially formed on the rear surface of the light absorbing layer on the projection surface, and the second electrode includes a first portion in direct contact with the second contact layer and a second portion located between the first portions.

A scalable voltage source having a number N of mutually series-connected partial voltage sources designed as semiconductor diodes, wherein each of the partial voltage sources comprises a p-n junction of a semiconductor diode, and each semiconductor diode has a p-doped absorption layer, wherein the p-absorption layer is passivated by a p-doped passivation layer with a wider band gap than the band gap of the p-absorption layer and the semiconductor diode has an n-absorption layer, wherein the n-absorption layer is passivated by an n-doped passivation layer with a wider band gap than the band gap of the n-absorption layer, and the partial source voltages of the individual partial voltage sources deviate by less than 20%, and between in each case two successive partial voltage sources, a tunnel diode is arranged.

A scalable voltage source having a number N of mutually series-connected partial voltage sources designed as semiconductor diodes, wherein each of the partial voltage sources comprises a p-n junction of a semiconductor diode, and each semiconductor diode has a p-doped absorption layer, wherein the p-absorption layer is passivated by a p-doped passivation layer with a wider band gap than the band gap of the p-absorption layer and the semiconductor diode has an n-absorption layer, wherein the n-absorption layer is passivated by an n-doped passivation layer with a wider band gap than the band gap of the n-absorption layer, and the partial source voltages of the individual partial voltage sources deviate by less than 20%, and between in each case two successive partial voltage sources, a tunnel diode is arranged.

A growth structure having a lattice transition (or graded buffer) or an engineered growth structure with a desired lattice constant, different from a lattice constant of conventional substrates like GaAs, Si, Ge, InP, under a release layer or an etch stop layer is used as a seed crystal for growing optoelectronic devices. The optoelectronic device can be a photovoltaic device having one or more subcells (e.g., lattice-matched or lattice-mismatched subcells). The release layer can be removed using different processes to separate the optoelectronic device from the growth structure, which may be reused, or from the engineered growth structure. When using the etch stop layer, the growth structure or the engineered growth structure may be grinded or etched away. The engineered growth structure may be made from a layer transfer process between two wafers or from a ternary and/or a quaternary material. Methods for making the optoelectronic device are also described.

A method is described that includes sputtering multiple layers on a back surface of the photovoltaic structure, the photovoltaic structure being made of at least one group III-V semiconductor material, and evaporating, over the multiple layers, one or more additional layers including a metal layer, the back metal structure being formed by the multiple layers and the additional layers. A photovoltaic device is also described that includes a back metal structure disposed over a back surface of a photovoltaic structure made of a group III-V semiconductor material, the back metal structure including one or more evaporated layers disposed over multiple sputtered layers, the one or more evaporated layers including a metal layer. By allowing evaporation along with sputtering, tool size and costs can be reduced, including minimizing a number of vacuum breaks. Moreover, good yield and reliability, such as reducing dark line defects (DLDs), can also be achieved.

Monolithic, lateral series photovoltaic and photodiode devices on an insulating substrate are provided. In one aspect, a method of forming a photovoltaic device includes: forming a photovoltaic stack on an insulating substrate that includes: a bottom contact layer disposed on the insulating substrate, a BSF layer disposed on the bottom contact layer, a junction layer disposed on the BSF layer, a window layer disposed on the junction layer, and a top contact layer disposed on the window layer; patterning the top contact layer, the window layer, the junction layer, the BSF layer and the bottom contact layer into individual device stacks; forming contact pads on patterned portions of the bottom/top contact layers in each of the device stacks; and forming interconnects in contact with the contact pads that serially connect the device stacks. A photovoltaic device is also provided.