A method of performing heteroepitaxy comprises exposing a substrate to a carrier gas, a first precursor gas, a Group II/III element, and a second precursor gas, to form a heteroepitaxial growth of one of GaAs, AlAs, InAs, GaP, InP, ZnSe, GaSe, CdSe, InSe, ZnTe, CdTe, GaTe, HgTe, GaSb, InSb, AlSb, CdS, GaN, and AlN on the substrate; wherein the substrate comprises one of GaAs, AlAs, InAs, GaP, InP, ZnSe, GaSe, CdSe, InSe, ZnTe, CdTe, GaTe, HgTe, GaSb, InSb, AlSb, CdS, GaN, and AlN; wherein the carrier gas is H.sub.2, wherein the first precursor is HCl, the Group II/III element comprises at least one of Zn, Cd, Hg, Al, Ga, and In; and wherein the second precursor is one of AsH.sub.3 (arsine), PH.sub.3 (phosphine), H.sub.2Se (hydrogen selenide), H.sub.2Te (hydrogen telluride), SbH.sub.3 (hydrogen antimonide), H.sub.2S (hydrogen sulfide), and NH.sub.3 (ammonia). The process may be an HVPE (hydride vapor phase epitaxy) process.

An unreleased thermopile IR sensor and method of fabrication is provided which includes a new thermally isolating material and an ultra-thin material based sensor which, in combination, provide excellent sensitivity without requiring a released membrane structure. The sensor is fabricated using a wafer transfer technique in which a substrate assembly comprising the substrate and new thermally isolating material is bonded to a carrier substrate assembly comprising a carrier substrate and the ultra-thin material, followed by removal of the carrier substrate. As such, temperature restrictions of the various materials are overcome.

A photovoltaic device includes a substrate, a transparent conductive oxide, an n-type window layer, a p-type absorber layer and an electron reflector layer. The electron reflector layer may include zinc telluride doped with copper telluride, zinc telluride alloyed with copper telluride, or a bilayer of multiple layers containing zinc, copper, cadmium and tellurium in various compositions. A process for manufacturing a photovoltaic device includes forming a layer over a substrate by at least one of sputtering, evaporation deposition, CVD, chemical bath deposition process, and vapor transport deposition process. The process includes forming an electron reflector layer over a p-type absorber layer.

According to the embodiments provided herein, a method for scribing a layer stack of a photovoltaic device can include directing a laser scribing waveform to a film side of a layer stack. The laser scribing waveform can include pulse groupings that repeat at a group repetition period of greater than or equal to 1.5 .Math.s. Each pulse of the pulse groupings can have a pulse width of less than or equal to 900 fs.

In general, this disclosure is directed to a flexible or stretchable sensor and a method of detecting a substance and/or electromagnetic radiation using said sensor. The sensor comprises a flexible or stretchable substrate, a pair of terminal electrodes disposed on the flexible or stretchable substrate in mutually spaced apart and opposing relation, and a sensing element applied to the flexible or stretchable substrate, between and in electrical contact with the pair of terminal electrodes, wherein the sensing element is responsive to a substance and/or electromagnetic radiation impinging thereon, and wherein when a voltage is applied across the sensor, an electrical signal is generated that is proportional to a resistance value corresponding to a sensing of the substance and/or electromagnetic radiation impinging on the sensing element.

A photoexcitation material includes: a wurtzite type solid solution crystal containing gallium, zinc, nitrogen and oxygen, wherein a peak (A) of an existence ratio of nitrogen or oxygen which is a first adjacent atom of the gallium or zinc and a peak (B) of an existence ratio of gallium or zinc which is a second adjacent atom of the gallium or zinc satisfy a relational expression of A>B in a relationship between a distance and the existence ratio of the adjacent atom of the gallium or zinc, the relationship being obtained from an extended X-ray absorption fine structure analysis.

A method of fabricating a buffer layer of a photovoltaic device comprises: providing a substrate having a back contact layer disposed above the substrate and an absorber layer disposed above the back contact layer; depositing a metal layer on the absorber layer; and performing a thermal treatment on the deposited metal layer in an atmosphere comprising sulfur, selenium or oxygen, to form a buffer layer.

Disclosed are ultrathin layers of group II-VI semiconductors, group II-VI semiconductor superlattice structures, photovoltaic devices incorporating the layers and superlattice structures and related methods. The superlattice structures comprise an ultrathin layer of a first group II-VI semiconductor alternating with an ultrathin layer of at least one additional semiconductor, e.g., a second group II-VI semiconductor, or a group IV semiconductor, or a group III-V semiconductor.

A method for manufacturing a large-area thin film solar cell includes the steps of: (a) forming a first contact layer on a substrate; (b) forming a multi-layer metal precursor film on the first contact layer, which includes the sub-steps of (b1) sputtering a first multinary metal precursor layer on the first contact layer, the first multinary metal precursor layer containing Cu, Ga and KF, and (b2) sputtering an In-containing precursor layer on the first multinary metal precursor layer; and (c) subjecting the multi-layer metal precursor film to selenization to form an absorber layer having a chalcopyrite phase.

A composition of matter, in particular a photovoltaic cell, comprising: at least one core semiconductor nanowire on a graphitic substrate, said at least one core nanowire having been grown epitaxially on said substrate wherein said nanowire comprises at least one group III-V compound or at least one group II-VI compound or at least one group IV element; a semiconductor shell surrounding said core nanowire, said shell comprising at least one group III-V compound or at least one group II-VI compound or at least one group IV element such that said core nanowire and said shell form a n-type semiconductor and a p-type semiconductor respectively or vice versa; and an outer conducting coating surrounding said shell which forms an electrode contact.