Photovoltaic devices including direct gap III-V absorber materials and operatively associated back structures enhance efficiency by enabling photon recycling. The back structures of the photovoltaic devices include wide bandgap III-V layers, highly doped (In)GaAs layers, patterned oxide layers and metal reflectors that directly contact the highly doped (In)GaAs layers through vias formed in the back structures. Localized ohmic contacts are formed in the back structures of the devices.

According to one embodiment, a photochemical reaction device comprises a laminated body and an ion transfer pathway. A laminated body comprises an oxidation catalyst layer for producing oxygen and protons by oxidizing water a reduction catalyst layer for producing carbon compounds by reducing carbon dioxide and a semiconductor layer formed between the oxidation catalyst layer and the reduction catalyst layer and developing charge separation with light energy. An ion transfer pathway moves ions between the oxidation catalyst layer side and the reduction catalyst layer side.

A monolithic multiple solar cell includes at least three partial cells, with a semiconductor mirror placed between two partial cells. The aim of the invention is to improve the radiation stability of said solar cell. For this purpose, the semiconductor mirror has a high degree of reflection in at least one part of a spectral absorption area of the partial cell which is arranged above the semiconductor mirror and a high degree of transmission within the spectral absorption range of the partial cell arranged below the semiconductor mirror.

A method of disordering a layer of an optoelectronic device including; growing a plurality of lower layers; introducing an isoelectronic surfactant; growing a layer; allowing the surfactant to desorb; and growing subsequent layers all performed at a low pressure of 25 torr.

A scalable voltage source having a number N of partial voltage sources implemented as semiconductor diodes connected to one another in series, wherein each of the partial voltage sources has a semiconductor diode with a p-n junction. A tunnel diode is formed between sequential pairs of partial voltage sources, wherein the tunnel diode has multiple semiconductor layers with a larger band gap than the band gap of the p/n absorption layers and the semiconductor layers with the larger band gap are each made of a material with modified stoichiometry and/or a different elemental composition than the p/n absorption layers of the semiconductor diode. The partial voltage sources and the tunnel diodes are monolithically integrated together, and jointly form a first stack with a top and a bottom, and the number N of partial voltage sources is greater than or equal to two.

The present disclosure provides interconnect elements and methods of using interconnect elements. In one embodiment, the interconnect element includes: a first end including at least three members, each member having a pair of parallel gap apertures for mounting an adjoining first component; a second opposing end including at least two members, each member having a pair of parallel gap apertures for mounting an adjoining second component; and one or more interconnect connecting portions to attach the first end of the interconnect element to the second end of the interconnect element.

An integrated thin-film lateral multi-junction solar device and fabrication method are provided. The device includes, for instance, a substrate, and a plurality of stacks extending vertically from the substrate. Each stack may include layers, and be electrically isolated against another stack. Each stack may also include an energy storage device above the substrate, a solar cell above the energy storage device, a transparent medium above the solar cell, and a micro-optic layer of spectrally dispersive and concentrating optical devices above the transparent medium. Furthermore, the device may include a first power converter connected between the energy storage device and a power bus, and a second power converter connected between the solar cell and the power bus. Further, different solar cells of different stacks may have different absorption characteristics.

A highly doped layer for interconnecting tunnel junctions in multijunction solar cells is presented. The highly doped layer is a delta doped layer in one or both layers of a tunnel diode junction used to connect two or more p-on-n or n-on-p solar cells in a multijunction solar cell. A delta doped layer is made by interrupting the epitaxial growth of one of the layers of the tunnel diode, depositing a delta dopant at a concentration substantially greater than the concentration used in growing the layer of the tunnel diode, and then continuing to epitaxially grow the remaining tunnel diode.

A compound photovoltaic cell includes a substrate, a first cell made of a first semiconductor material and formed on the substrate, a tunnel layer, and a second cell made of a second semiconductor material lattice mismatched with a material of the substrate, connected to the first cell via the tunnel layer, and disposed on an incident side with respect to the first cell, wherein band gaps of the first and the second cells become smaller from an incident side to a back side, and wherein the tunnel layer includes a p-type layer disposed on the incident side and a n-type layer disposed on the back side, the p-type layer being a p.sup.+-type (Al)GaInAs layer, the n-type layer being an n.sup.+-type InP layer, an n.sup.+-type GaInP layer having a tensile strain with respect to InP or n.sup.+-type Ga(In)PSb layer having a tensile strain with respect to InP.

This disclosure relates to semiconductor devices and methods for fabricating semiconductor devices. Particularly, the disclosure relates to back-contact-only multijunction solar cells and the process flows for making such solar cells, including a wet etch process that removes semiconductor materials non-selectively without major differences in etch rates between heteroepitaxial III-V semiconductor layers.