Methods for removing a material layer from a base substrate utilizing spalling in which mode III stress, i.e., the stress that is perpendicular to the fracture front created in the base substrate, during spalling is reduced. The substantial reduction of the mode III stress during spalling results in a spalling process in which the spalled material has less surface roughness at one of its' edges as compared to prior art spalling processes in which the mode III stress is present and competes with spalling.

A surface-mountable semiconductor component and a method for producing the same are disclosed. In an embodiment the component includes an optoelectronic semiconductor chip, first and second contact elements and a molded body, wherein the chip includes a semiconductor body having a semiconductor layer sequence with an active region provided for producing and/or receiving electromagnetic radiation and arranged between a first semiconductor layer and a second semiconductor layer, wherein the first contact elements are electrically conductively connected to the first semiconductor layer and the second contact elements are electrically conductively connected to the second semiconductor layer, wherein the molded body at least partially encloses the optoelectronic semiconductor chip, wherein the semiconductor component includes a mounting face formed by a surface of the molded body, and wherein the first and second contact elements protrudes through the molded body in a region of the mounting face.

An optoelectronic device having a textured layer is described. In an aspect, a method may be used to produce the optoelectronic device, where the method includes epitaxially growing a semiconductor layer of the optoelectronic device on a growth substrate, and exposing the semiconductor layer to an etching process to create at least one textured surface in the semiconductor layer. The textured semiconductor layer can be referred to as a textured layer. The etching process is performed without the use of a template layer, or similar layer, configured as a mask to generate the texturing. The etching process can be done by one or more of a liquid or solution-based chemical etchant, gas etching, laser etching, plasma etching, or ion etching. The method can also include lifting the semiconductor layer of the optoelectronic device from the growth substrate by, for example, the use of an epitaxial lift off (ELO) process.

This disclosure provides systems, methods, and apparatus related to photodetectors. In one aspect, a photodetector device comprises a substrate, a polycrystalline layer disposed on the substrate, and a first electrode and a second electrode disposed on the polycrystalline layer. The polycrystalline layer comprises nanograins with grain boundaries between the nanograins. The nanograins comprise a semiconductor material. A doping element comprising a halogen is segregated at the grain boundaries. A length of the polycrystalline layer is between and separating the first electrode and the second electrode.

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.

Techniques for processing materials for manufacture of gallium-containing nitride substrates are disclosed. More specifically, techniques for fabricating and reusing large area substrates using a combination of processing techniques are disclosed. The methods can be applied to fabricating substrates of GaN, AlN, InN, InGaN, AlGaN, and AlInGaN, and others. Such substrates can be used for a variety of applications including optoelectronic devices, lasers, light emitting diodes, solar cells, photo electrochemical water splitting and hydrogen generation, photo detectors, integrated circuits, transistors, and others.

MOSFET phototransistors, methods of operating the MOSFET phototransistors and methods of making the MOSFET phototransistors are provided. The phototransistors have a buried electrode configuration, which makes it possible to irradiate the entire surface areas of the radiation-receiving surfaces of the phototransistors.

A thickness of material may be detached from a substrate along a cleave plane, utilizing a cleaving process controlled by a releasable constraint plate. In some embodiments this constraint plate may comprise a plate that can couple side forces (the P-plate) and a thin, softer compliant layer (the S-layer) situated between the P-plate and the substrate. In certain embodiments a porous surface within the releasable constraint plate and in contact to the substrate, allows the constraint plate to be secured to the substrate via a first pressure differential. Application of a combination of a second pressure differential within a pre-existing cleaved portion, and a linear force to a side of the releasable constraint plate bound to the substrate, generates loading that results in controlled cleaving along the cleave plane.

A method for forming a back contact on an absorber layer in a photovoltaic device includes forming a two dimensional material on a first substrate. An absorber layer including CuZnSnS(Se) (CZTSSe) is grown over the first substrate on the two dimensional material. A buffer layer is grown on the absorber layer on a side opposite the two dimensional material. The absorber layer is exfoliated from the two dimensional material to remove the first substrate from a backside of the absorber layer opposite the buffer layer. A back contact is deposited on the absorber layer.

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