The present disclosure provides a multijunction solar cell that includes: a first sequence of layers of semiconductor material forming a first set of one or more solar subcells; a graded interlayer adjacent to said first sequence of layers; a second sequence of layers of semiconductor material forming a second set of one or more solar subcells; and a high band gap contact layer adjacent said second sequence of layers, wherein the high band gap contact layer is composed of p++ type InGaAlAs or InGaAs.

A growth structure having a lattice transition under a release layer is used as a seed crystal for growth of optoelectronic devices. The optoelectronic device can be a single- or multi-junction photovoltaic device. The release layer can be selectively removed in an epitaxial lift-off (ELO) process to separate the optoelectronic device from the growth structure and leave the region with the lattice transition intact to reuse the growth structure to grow additional devices. A manufacturing method is described that includes providing a growth structure having a substrate and a lattice transition from a first lattice constant to a second lattice constant, depositing a release layer on the growth structure, depositing on the release layer an epitaxial layer having a lattice constant that matches the second lattice and including an optoelectronic device, and removing the release layer to separate the epitaxial layer and the optoelectronic device from the growth structure.

The present disclosure provides a solar cell array for deployment and use in a space environment, and methods of making same. The array includes a plurality of solar cells having an emissivity coating on the baskside of each, with each coated solar cell being attached to a supporting member.

The disclosure describes multi-junction solar cell structures that include two or more graded interlayers.

A method for producing a multiplicity of semiconductor chips (13) is provided, comprising the following steps: providing a wafer (1) comprising a multiplicity of semiconductor bodies (2), wherein separating lines (9) are arranged between the semiconductor bodies (2), depositing a contact layer (10) on the wafer (1), wherein the material of the contact layer (10) is chosen from the following group: platinum, rhodium, palladium, gold, and the contact layer (10) has a thickness of between 8 nanometers and 250 nanometers, inclusive, applying the wafer (1) to a film (11), at least partially severing the wafer (1) in the vertical direction along the separating lines (9) or introducing fracture nuclei (12) into the wafer (1) along the separating lines (9), and breaking the wafer (1) along the separating lines (9) or expanding the film (11) such that a spatial separation of the semiconductor chips (13) takes place, wherein the contact layer (10) is also separated. A semiconductor chip, a component and a method for producing the latter are also provided.

Photoactive devices include an active region disposed between first and second electrodes and configured to absorb radiation and generate a voltage between the electrodes. The active region includes an active layer comprising a semiconductor material exhibiting a relatively low bandgap. The active layer has a front surface through which radiation enters the active layer and a relatively rougher back surface on an opposing side of the active layer. Methods of fabricating photoactive devices include the formation of such an active region and electrodes.

The present disclosure provides a method of manufacturing a solar cell that includes providing a semiconductor growth substrate; depositing on said growth substrate a sequence of layers of semiconductor material forming a solar cell; applying a metal contact layer over said sequence of layers; affixing the adhesive polyimide surface of a permanent supporting substrate directly over said metal contact layer and permanently bonding it thereto by a thermocompressive technique; and removing the semiconductor growth substrate.

A multijunction solar cell assembly and its method of manufacture including interconnected first and second discrete semiconductor body subassemblies disposed adjacent and parallel to each other, each semiconductor body subassembly including first top subcell, second (and possibly third) lattice matched middle subcells; a graded interlayer adjacent to the last middle solar subcell; and a bottom solar subcell adjacent to said graded interlayer being lattice mismatched with respect to the last middle solar subcell; wherein the interconnected subassemblies form at least a four junction solar cell by a series connection being formed between the bottom solar subcell in the first semiconductor body and the bottom solar subcell in the second semiconductor body.

A multijunction solar cell includes an InGaAs buffer layer and an InGaAlAs grading interlayer disposed below, and adjacent to, the InGaAs buffer layer. The grading interlayer achieves a transition in lattice constant from one solar subcell to another solar subcell.

A multi-junction optoelectronic device and method of manufacture are disclosed. The method comprises providing a first p-n structure on a substrate, wherein the first p-n structure comprises a first base layer of a first semiconductor with a first bandgap such that a lattice constant of the first semiconductor matches a lattice constant of the substrate, and wherein the first semiconductor comprises a Group III-V semiconductor. The method includes providing a second p-n structure, wherein the second p-n structure comprises a second base layer of a second semiconductor with a second bandgap, wherein a lattice constant of the second semiconductor matches a lattice constant of the first semiconductor, and wherein the second semiconductor comprises a Group IV semiconductor. The method also includes lifting off the substrate the multi-junction optoelectronic device having the first p-n structure and the second p-n structure, wherein the multi-junction optoelectronic device is a flexible device.