A photodetector includes a metal layer that shields incident light and generates surface plasmon polaritons (SPPs), a light absorbing layer that absorbs the generated SPPs and allows charges excited by the absorbed SPPs and a localized electric field effect to tunnel, a dielectric formed at nanoholes in which at least a part of the metal layer is opened, and a semiconductor layer that induces the photocurrent based on an electric field effect of tunneled electrons. The SPPs form localized surface plasmons (LSPs) at an interface where the metal layer meets the dielectric.

A semiconductor device has a layered structure. The semiconductor device includes a metallic layer of thickness 1-100 nm, with a thickness optimized to absorb light in a wavelength range of operation. The device further includes an adjacent semiconductor layer additionally adjacent to an ohmic electrical contact, wherein the interface between the metallic layer and the semiconductor layer is electrically rectifying and energy selective. The device further includes a reflective back surface positioned opposite to the semiconductor layer relative to incident light providing broadband reflection in the wavelength range of operation. The semiconductor layer includes a quantum well adjacent to the metallic layer, wherein the energy selectivity is provided by the quantum well allowing charge carrier tunneling from the metallic layer. The device further may include an additional anti-reflection dielectric layer deposited on the metallic layer that is configured to minimize reflection of light in the wavelength range of operation.

Aspects of embodiments relate to an optical transceiver device, comprising: a detection region for detecting light at a first wavelength for down-conversion; and a modulation region for modulating light at a second wavelength longer than the first wavelength, wherein the detection region is substantially transparent to light at the second wavelength and located upstream to the modulation with respect to direction of propagation of first wavelength light incident onto the detection region.

A ballistic carrier spectral sensor includes a photon absorption region to generate photo-generated carriers from incident light; a first potential barrier region adjacent the photon absorption region and having an adjustable height defining a minimum energy of the photo-generated carriers required to pass therethrough; a second potential barrier region having an adjustable height defining a minimum energy of the photo-generated carriers required to pass therethrough; a spillage well region disposed between the first potential barrier region and the second potential barrier region and configured to collect photo-generated carriers having an energy lower than that required to pass through the second potential barrier region; and a collection region adjacent the second potential barrier region and configured to collect carriers that cross the second potential barrier region. A total thickness of the first potential barrier region and the spillage well region is less than a mean free path of the photo-generated carriers.

A method of fabricating an Ag(Cu)InGaSe (A(C)IGS) based thin film using SeAg.sub.2Se core-shell nanoparticles, an A(C)IGS based thin film fabricated by the method, and a tandem solar cell having the A(C)IGS thin film are disclosed. More particularly, a method of fabricating a densified Ag(Cu)InGaSe (A(C)IGS) based thin film by non-vacuum coating a substrate with a slurry containing SeAg.sub.2Se core-shell nanoparticles, an A(C)IGS based thin film fabricated by the method, and a tandem solar cell including the A(C)IGS based thin film are disclosed. According to the present invention, an A(C)IGS based thin film including Ag is manufactured by applying SeAg.sub.2Se core-shell nanoparticles in a process of manufacturing a (C)IGS thin film, thereby providing an A(C)IGS based thin film having a wide band gap.

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.

A semiconductor device employs an epitaxial layer arrangement including a first ohmic contact layer and first modulation doped quantum well structure disposed above the first ohmic contact layer. The first ohmic contact layer has a first doping type, and the first modulation doped quantum well structure has a modulation doped layer of a second doping type. At least one isolation ion implant region is provided that extends through the first ohmic contact layer. The at least one isolation ion implant region can include oxygen ions. The at least one isolation ion implant region can define a region that is substantially free of charge carriers in order to reduce a characteristic capacitance of the device. A variety of high performance transistor devices (e.g., HFET and BICFETs) and optoelectronic devices can employ this device structure. Other aspects of wavelength-tunable microresonantors and related semiconductor fabrication methodologies are also described and claimed.

Embodiments of the present disclosure are directed to infrared detector devices incorporating a tunneling structure. In one embodiment, an infrared detector device includes a first contact layer, an absorber layer adjacent to the first contact layer, and a tunneling structure including a barrier layer adjacent to the absorber layer and a second contact layer adjacent to the barrier layer. The barrier layer has a tailored valence band offset such that a valence band offset of the barrier layer at the interface between the absorber layer and the barrier layer is substantially aligned with the valence band offset of the absorber layer, and the valence band offset of the barrier layer at the interface between the barrier layer and the second contact layer is above a conduction band offset of the second contact layer.

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.

Methods are provided for controlling the shape of antimony selenide (Sb.sub.2Se.sub.3) synthesized nanostructures. The method dissolves an antimony (III) salt in a first amount of carboxylic acid, forming an antimony precursor. In one aspect, antimony (III) chloride is dissolved in oleic acid. Separately, selenourea is dissolved in oleylamine, forming a selenium precursor. The antimony precursor is combined with the selenium precursor to form a first solution and cause a reaction. The reaction is quenched with a solvent having a low boiling point. In response to quenching the reaction in the first solution, antimony selenide nanorods are formed, having a length in the range of 150-200 nanometers (nm) and a diameter in the range of 20 to 30 nm. Related methods can be used to create, shorter nanorods, nanocrystals, and hollow nanospheres.