An X-ray detector according to the present disclosure comprises: a scintillator for converting incident X-rays into visible rays; a photoelectric conversion part, which is disposed below the scintillator and converts the visible rays into electrical signals; and a substrate disposed below the photoelectric conversion part, wherein the scintillator comprises a perovskite compound represented by the following chemical formula 1. [Chemical Formula 1] A.sub.3B.sub.2X.sub.5:Activator (In the chemical formula, A is a monovalent metal cation, B is a divalent metal cation, X is a monovalent anion, and the activator is thallium (Tl) or indium (In).)

A device includes a substrate and a heterostructure supported by the substrate. The heterostructure includes a set of quantum dot structures, each quantum dot structure of the set of quantum dot structures including a semiconductor material, and a layered material disposed between the set of quantum dot structures and the substrate. The layered material includes a plurality of monolayers such that adjacent monolayers of the plurality of monolayers are bonded to one another via van der Waals forces, and the semiconductor material of each quantum dot structure of the set of quantum dot structures exhibits bonding via van der Waals forces.

Plasmonic substrates are provided which may be used in a variety of optoelectronic devices, e.g., biosensors and photodetectors. The plasmonic substrate may comprise a layer of graphene and a plurality of discrete, individual transition metal chalcogenide nanodomes distributed on a surface of the layer of graphene, each nanodome surrounded by bare graphene. Methods for making and using the plasmonic substrates are also provided.

A ultraviolet detector includes a substrate; a first epitaxial layer that is a heavily doped epitaxial layer and located on the substrate, a second epitaxial layer located on the first epitaxial layer, where the second epitaxial layer is a lightly doped epitaxial layer, or a double-layer or multi-layer structure composed of at least one lightly doped epitaxial layer and at least one heavily doped epitaxial layer; an ohmic contact layer located on the second epitaxial layer or formed in the second epitaxial layer, where the ohmic contact layer is a graphical heavily doped layer; and a first metal electrode layer located on the ohmic contact layer.

A plurality of holes in a top surface of a silicon medium form a plurality of sub-meta lenses to result in multiple focal points rather than a single point (resulting from using a single meta lens). As a result, optical paths for incoming light are reduced as compared with a single optical path associated with a single meta lens, which in turn reduces angular response of incident photons. Thus, a pixel sensor including the plurality of sub-meta lenses experiences improved light focus and greater signal-to-noise ratio. Additionally, dimensions of the pixel sensor are reduced (particularly a height of the pixel sensor), which allows for greater miniaturization of an image sensor that includes the pixel sensor.

Disclosed are a light emitting diode unit for harvesting energy and a display module. The light emitting diode unit comprises: a substrate; a light emitting diode arranged on the substrate; and an energy harvesting member comprising a semiconductor layer surrounding the light emitting diode and configured to absorb light energy emitted by the light emitting diode, to generate electric energy, wherein an inner surface of the energy harvesting member is spaced apart from the light emitting diode.

A dynamic photodiode detector or detector array having a light absorbing region of doped semiconductor material for absorbing photons. Electrons or holes generated by photon absorption are detected with a construction of oppositely heavily doped anode and cathode regions and a heavily doped ground region of the same doping type as the anode region. Photon detection involves switching the device from reverse bias to forward bias to create a depletion region enclosing the anode region. When a photon is then absorbed the electron or hole thereby generated drifts under the electric field induced by the biasing to the depletion region where it causes the anode-to-ground current to increase. Furthermore, the detector is configured such that anode-to-cathode current starts to flow once a threshold number of electrons or holes reaches the depletion region, where the threshold may be one to provide single photon detection.

Systems, methods and apparatus related to a multijunction solar cell. The apparatus comprises a first sub-solar cell, a second sub-solar cell in series with the first sub-solar cell and one or more quantum wells. At least some of the quantum wells are disposed in a region of the first sub-solar cell, and have a thickness and a bandgap sized such that a bandgap in selected quantum wells are less than a bandgap of a material of the first sub-solar cell and greater than a bandgap of a material of the second sub-solar cell resulting in radiative coupling between the first sub-solar cell and the second sub-solar cell.

A monolithic optoelectronic integrated circuit is provided, including: a substrate including photonic integrated device region and a peripheral circuit region; a first GaN-based multi-quantum well optoelectronic PN-junction device including a first P-type ohmic contact electrode and a first N-type ohmic contact electrode; and a first GaN-based field-effect transistor, where the first GaN-based field-effect transistor includes a first gate dielectric layer disposed on the surface of the substrate and having a first recess, a first gate filled within the first recess, and a first source and a first drain that are disposed the opposite sides of the first gate, where the first source is electrically connected to the first P-type ohmic contact electrode, the first drain is configured to be electrically connected to a first potential.

A differential amplifier includes an unmatched pair, including first quantum dots and second quantum dots, and a matched pair, including first and second phototransistors. The unmatched pair has a difference between a first spectrum absorbed by the first quantum dots and a second spectrum absorbed by the second quantum dots. Each of the first and second phototransistors includes a channel. The first quantum dots absorb the first spectrum from incident electromagnetic radiation and gate a first current through the channel of the first phototransistor, and the second quantum dots absorb the second spectrum from the incident electromagnetic radiation and gate a second current through the channel of the second phototransistor. The first and second phototransistors are coupled together for generating a differential output from the first and second currents, the differential output corresponding to the difference between the first and second spectrums within the incident electromagnetic radiation.