A multijunction solar cell and its method of fabrication, including an upper and a lower solar subcell each having an emitter layer and a base layer forming a photoelectric junction; a near infrared (NIR) wideband reflector layer disposed below the upper subcell and above the lower subcell for reflecting light in the spectral range of 900 to 1050 nm which represents unused and undesired solar energy and thereby reducing the overall solar energy absorptance in the solar cell and providing thermodynamic radiative cooling of the solar cell when deployed in space outside the atmosphere.

Provided are an infrared detecting device and an infrared detecting system including the infrared detecting device. The infrared detecting device includes at least one infrared detector, and the at least one infrared detector includes a substrate, a buffer layer, and at least one light absorbing portion. The buffer layer includes a superlattice structure.

A device for producing electricity. In one embodiment, the device comprises a doped germanium or a doped GaAs substrate and a plurality of stacked material layers (some of which are doped) above the substrate. These stacked material layers, which capture beta particles and generate electrical current, may include, in various embodiments, GaAs, InAlP, InGaP, InAlGaP, AlGaAs, and other semiconductor materials. A radioisotope source generates beta particles that impinge the stack, create electron-hole pairs, and thereby generate electrical current. In another embodiment the device comprises a plurality of epi-liftoff layers and a backing support material. The devices can be connected in series or parallel.

Monolithic pixel detectors, systems and methods for the detection and imaging of electromagnetic radiation with high spectral and spatial resolution comprise a Si wafer with a CMOS processed pixel readout bonded to an absorber wafer in wafer bonds comprising conducting bonds between doped, highly conducting charge collectors in the readout and highly conducting regions in the absorber wafer and poorly conducting bonds between regions of high resistivity.

A multijunction solar cell including a growth substrate; a graded interlayer disposed over the growth substrate, a plurality of subcells disposed over the graded interlayer including a second solar subcell disposed over and lattice mismatched with respect to the growth substrate, and at least a third solar subcell disposed over the second subcell; the grading interlayer including a plurality of N step-graded sublayers (where N is an integer and the value of N is 1<N<10), wherein each successive sublayer has an incrementally greater lattice constant than the sublayer below it and grown in such a manner that each sublayer is fully relaxed, a distributed Bragg reflector (DBR) layer over the grading interlayer and an upper solar subcell disposed over the third solar subcell, a band gap in the range of 1.95 to 2.20 eV, and composed of a semiconductor compound including at least indium, aluminum and phosphorus.

A photodiode, such as a linear mode avalanche photodiode can be made free of excess noise via having a superlattice multiplication region that allows only one electrical current carrier type, such as an electron or a hole, to accumulate enough kinetic energy to impact ionize when biased, where the layers are lattice matched. A photodiode can be constructed with i) a lattice matched pair of a first semiconductor alloy and a second semiconductor alloy in a superlattice multiplication region, ii) an absorber region, and iii) a semiconductor substrate. A detector with multiple photodiodes can be made with these construction layers in order to have a cutoff wavelength varied anywhere from 1.7 to 4.9 μm as well as a noise resulting from a dark current at a level such that an electromagnetic radiation signal with the desired minimum wavelength cutoff can be accurately sensed by the photodiode.

Methods and apparatus for processing a photonic device are provided herein. For example, methods include etching, using a plasma etch process that uses a first gas, a first epitaxial layer of material of the photonic device comprising a base layer comprising at least one of silicon, germanium, sapphire, aluminum indium gallium arsenide (Al.sub.xIn.sub.yGa.sub.1-x-yAs), aluminum indium gallium phosphide (Al.sub.xIn.sub.yGa.sub.1-x-yP), aluminum indium gallium nitride (Al.sub.xIn.sub.yGa.sub.1-x-yN), aluminum indium gallium arsenide phosphide (Al.sub.xIn.sub.yGa.sub.1-x-yAs.sub.zP.sub.1-z), depositing, using a plasma deposition process that uses a second gas different from the first gas, a first dielectric layer over etched sidewalls of the first epitaxial layer of material, etching, using the first gas, a second epitaxial layer of material of the photonic device, and depositing, using the second gas, a second dielectric layer over etched sidewalls of the second epitaxial layer of material.

The present invention is a method for producing an electronic device having a drive circuit including a solar cell structure, the method including the steps of: obtaining a bonded wafer by bonding a first wafer having a plurality of independent solar cell structures including a compound semiconductor, the solar cell structures being formed on a starting substrate by epitaxial growth, and a second wafer having a plurality of independent drive circuits formed, so that the plurality of solar cell structures and the plurality of drive circuits are respectively superimposed; wiring the bonded wafer so that electric power can be supplied from the plurality of solar cell structures to the plurality of drive circuits respectively; and producing an electronic device having the drive circuit including the solar cell structure by dicing the bonded wafer. This provides a method for producing an electronic device including a drive circuit and a solar cell structure in one chip and having a suppressed production cost.

The technology relates to producing an optoelectronic device. A method for forming an optoelectronic device on a substrate may include growing an epitaxial structure on the substrate, wherein the substrate comprises a semiconductor material having a lattice constant between 5.7 and 6.0 Angstroms, and wherein the epitaxial structure includes an epitaxial device layer, then depositing a metal layer on the epitaxial structure, and selectively removing the epitaxial layer, thereby separating the optoelectronic device from the substrate. An optoelectronic device may include an optoelectronic device structure including an epitaxial device layer having a lattice constant between 5.7 and 6.0 Angstroms, a metal layer deposited onto a surface of the optoelectronic device structure, and a carrier structure, wherein the optoelectronic device comprises a thin film, single crystal device.

A solar cell comprising an epitaxial sequence of layers of semiconductor material thrilling at least a first and second solar subcells; a semiconductor contact layer disposed on the bottom surface of the second solar subcell; a reflective metal layer disposed below the semiconductor contact layer such that the reflectivity of the reflective metal layer is greater than 80% in the wavelength range 850 to 2000 nm, for reflecting light back into the second solar subcell.