A photodetector device includes a germanium semiconductor layer including a plurality of nanostructures at an upper surface of the germanium semiconductor layer, a conductive layer on the plurality of nanostructures, the conductive layer and the germanium semiconductor layer forming a first Schottky junction, and a tunneling barrier layer between the germanium semiconductor layer and the conductive layer.

Embodiments of the present disclosure relates to the field of solar cells, and in particular to a solar cell and a photovoltaic module. The solar cell includes: a substrate having a front surface and a rear surface; a first tunnel layer and a first doped conductive layer sequentially formed over the front surface of the substrate, the first tunnel layer and the first doped conductive layer are each aligned with a metal pattern region on the front surface; and a second tunnel layer and a second doped conductive layer sequentially formed over the rear surface of the substrate, and in a respective Raman spectrum, a full width at half maximum corresponding to the first doped conductive layer is not greater than a full width at half maximum corresponding to the second doped conductive layer.

An integrated microwave photonics (IMWP) apparatus is provided using sapphire as a platform. The IMWP apparatus includes: a sapphire substrate having a step-terrace surface; and a III-V stack layer epitaxially grown on the sapphire substrate. The III-V stack layer includes: a first III-V layer disposed on the sapphire substrate; a low temperature (LT) III-V buffer layer disposed on the first III-V layer; multiple second III-V layers disposed and stacked on the LT III-V buffer layer; a third III-V layer disposed on the second III-V layers; a III-V quantum well layer disposed on the third III-V layers; and a fourth III-V layer disposed on the III-V quantum well layer. The second III-V layers are respectively annealed. A growth temperature of the LT III-V layer and a growth temperature of the III-V quantum well layer are lower than a growth temperature of each of the first, second, third and fourth III-V layers.

In one aspect, optoelectronic devices are described herein. In some implementations, an optoelectronic device comprises a photovoltaic cell. The photovoltaic cell comprises a space-charge region, a quasi-neutral region, and a low bandgap absorber region (LBAR) layer or an improved transport (IT) layer at least partially positioned in the quasi-neutral region of the cell.

In accordance with an embodiment, a diode comprises a substrate, a dielectric material including an opening that exposes a portion of the substrate, the opening having an aspect ratio of at least 1, a bottom diode material including a lower region disposed at least partly in the opening and an upper region extending above the opening, the bottom diode material comprising a semiconductor material that is lattice mismatched to the substrate, a top diode material proximate the upper region of the bottom diode material, and an active diode region between the top and bottom diode materials, the active diode region including a surface extending away from the top surface of the substrate.

A photoluminescent liquid crystal display includes: a liquid crystal panel including a lower substrate, an upper substrate, a liquid crystal layer interposed between the upper and lower substrates, and a photoluminescent color filter layer disposed between the upper substrate and the liquid crystal layer; an optical device disposed on the upper substrate; a polarizing plate disposed under the lower substrate; and a backlight unit disposed under the polarizing plate and which emits blue light, where the photoluminescent color filter layer includes a first color filter which emits polarized red light, a second color filter which emits polarized green light, and a third color filter which emits polarized blue light, and the first color filter and the second color filter include a semiconductor nanocrystal-polymer composite.

Certain embodiments of the present invention may be directed to a transistor structure. The transistor structure may include a semiconductor substrate. The semiconductor substrate may include a drift region, a collector region, an emitter region, and a lightly-doped/undoped region. The lightly-doped/undoped region may be lightly-doped and/or undoped. The transistor structure may also include a heterostructure. The heterostructure forms a heterojunction with the lightly-doped/undoped region. The transistor structure may also include a collector terminal. The collector terminal is in contact with the collector region. The transistor structure may also include a gate terminal. The gate terminal is in contact with the heterostructure. The transistor structure may also include an emitter terminal. The emitter terminal is in contact with the lightly-doped/undoped region and the emitter region.

The present invention provides materials, structures, and methods for III-nitride-based devices, including epitaxial and non-epitaxial structures useful for III-nitride devices including light emitting devices, laser diodes, transistors, detectors, sensors, and the like. In some embodiments, the present invention provides metallo-semiconductor and/or metallo-dielectric devices, structures, materials and methods of forming metallo-semiconductor and/or metallo-dielectric material structures for use in semiconductor devices, and more particularly for use in III-nitride based semiconductor devices. In some embodiments, the present invention includes materials, structures, and methods for improving the crystal quality of epitaxial materials grown on non-native substrates. In some embodiments, the present invention provides materials, structures, devices, and methods for acoustic wave devices and technology, including epitaxial and non-epitaxial piezoelectric materials and structures useful for acoustic wave devices. In some embodiments, the present invention provides metal-base transistor devices, structures, materials and methods of forming metal-base transistor material structures for use in semiconductor devices.

The present invention discloses a photo-detector comprising: an n-type photon absorbing layer of a first energy bandgap; a middle barrier layer, an intermediate layer is a semiconductor structure; and a contact layer of a third energy bandgap, wherein the layer materials are selected such that the first energy bandgap of the photon absorbing layer is narrower than that of said middle barrier layer; wherein the material composition and thickness of said intermediate layer are selected such that the valence band of the intermediate layer lies above the valence band in the barrier layer to create an efficient trapping and transfer of minority carriers from the barrier layer to the contact layer such that a tunnel current through the barrier layer from the contact layer to the photon absorbing layer is less than a dark current in the photo-detector and the dark current from the photon-absorbing layer to said middle barrier layer is essentially diffusion limited and is due to the unimpeded flow of minority carriers, thus reducing generation-recombination (GR) noise of the photo-detector. The principles of the present invention also apply to inverted polarity structures of the form pBp in which all the doping polarities and band alignments described above are reversed.

According to one aspect, the invention relates to an element for quantum photodetection of an incident radiation in a spectral band centered around a central wavelength .sub.0, having a front surface intended for receiving said radiation, and including: a stack of layers of semiconductor material forming a PN or PIN junction and including at least one layer made of an absorbent semiconductor material having a cut-off wavelength .sub.0>.sub.0, the stack of layers of semiconductor material forming a resonant optical cavity; and a structure for coupling the incident radiation with the optical cavity such as to form a resonance at the central wavelength .sub.0 allowing the absorption of more than 80% in the layer of absorbent semiconductor material at said central wavelength, and an absence of resonance at the radiative wavelength .sub.rad, wherein the radiative wavelength .sub.rad is the wavelength for which, at operating temperature, the radiative recombination rate is the highest.