Abstract: A photodiode according to an embodiment includes a semiconductor substrate, a Schottky junction structure layer disposed on the semiconductor substrate and including a first layer including a conductive material and a semiconductor layer, and a pinning layer disposed adjacent to the Schottky junction structure layer and fixing potentials of the semiconductor substrate and the first layer.

Abstract: Provided are light emission devices including an output coupler and optical apparatuses having the same. The light emission device may include a QD layer containing quantum dots and a nano-antenna structure including an output coupler configured to control an output characteristic of light emitted from the QD layer. The output coupler may be configured to output an emission wavelength of the QD layer. The nano-antenna structure may include one of a metallic antenna, a dielectric antenna, and a slit-containing structure, or may have a multi-patch antenna structure or a fishbone antenna structure.

Abstract: Provided are light emission devices including an output coupler and optical apparatuses having the same. The light emission device may include a QD layer containing quantum dots and a nano-antenna structure including an output coupler configured to control an output characteristic of light emitted from the QD layer. The output coupler may be configured to output an emission wavelength of the QD layer. The nano-antenna structure may include one of a metallic antenna, a dielectric antenna, and a slit-containing structure, or may have a multi-patch antenna structure or a fishbone antenna structure.

Abstract: A two-dimensional (2D) spectroscopy system and a 2D spectroscopic analysis method are disclosed. The 2D spectroscopy system includes: a light transmission delayer configured for forming a plurality of first light pulses from first light pulse and causing a relative time delay therebetween; a response pulse wave generator configured for generating a plurality of response pulse waves responds and having a relative time delay, and for irradiating the plurality of response pulse waves on the sample; an optical readout pulse array generator configured for forming an optical readout pulse array by splitting the second light pulse into a plurality of regions having different time delays and spatially discriminated from one another; and a reader configured for reading out by overlapping the optical readout pulse array with a signal generated from the sample.

Abstract: A two-dimensional (2D) spectroscopy system and a 2D spectroscopic analysis method are disclosed. The 2D spectroscopy system includes: a light transmission delayer configured for forming a plurality of first light pulses from first light pulse and causing a relative time delay therebetween; a response pulse wave generator configured for generating a plurality of response pulse waves responds and having a relative time delay, and for irradiating the plurality of response pulse waves on the sample; an optical readout pulse array generator configured for forming an optical readout pulse array by splitting the second light pulse into a plurality of regions having different time delays and spatially discriminated from one another; and a reader configured for reading out by overlapping the optical readout pulse array with a signal generated from the sample.

Abstract: An electronic mirror and a method for displaying an image using the electronic mirror are provided. The electronic mirror may include a display unit, a detecting unit and a control unit. The detecting unit may receive a signal transmitted from the outside. The control unit may control the detecting unit and the display unit to display the signal received at the detecting unit on the display unit as an image. The image displayed on the display unit may be output from the electronic mirror through the detecting unit. The electronic mirror may further include a reflecting unit. A light from the outside may pass through the detecting unit and the display unit and then be reflected on the reflecting unit. The reflected light may be output from the electronic mirror through the display unit and the detecting unit.

Abstract: Electromagnetic wave oscillators each having a multi-tunnel and electromagnetic wave generating apparatuses including the electromagnetic wave oscillators are provided. The electromagnetic wave oscillator includes: a first waveguide which has a folded structure such that a path traveled by an electromagnetic wave through the first waveguide crosses an axial direction a plurality of times; an electron beam tunnel through which an electron beam passes, wherein the electron beam tunnel extends along the axial direction and crosses the first waveguide a plurality of times; and at least one auxiliary tunnel which extends parallel to the electron beam tunnel and which crosses the first waveguide a plurality of times.

Abstract: A terahertz interaction circuit is provided. The terahertz interaction circuit includes a waveguide and an electron beam tunnel. The waveguide has a folded shape and in which an electromagnetic wave propagates. The electron beam tunnel is formed to penetrate through the waveguide. An electron beam passes through the electron beam tunnel. The waveguide includes a ridge portion in which a portion of a surface of the waveguide protrudes into the waveguide.

Abstract: An electron beam focusing electrode and an electron gun using the same may include a plate having a polygonal through-hole; at least a projecting portion formed on at least one side of the through-hole. By using the electron beam focusing electrode, a spreading phenomenon of an electron beam having a rectangular cross section may be reduced. Further, the output of the electron gun may be increased, and electron beams may be easily focused.

Abstract: A terahertz interaction circuit includes a waveguide through which electromagnetic waves pass, the waveguide having a folded shape and including a narrow open cavity portion; and an electron beam tunnel through which an electron beam passes, the electron beam tunnel penetrating through the waveguide.

Abstract: A solar cell includes a plurality of nanowires arranged such that diameters of the nanowires sequentially increase in a first direction along a path of incident light. In a method of forming nanowires, a catalyst layer is formed on a substrate, a plurality of nanoparticles are formed by thermally processing the catalyst layer, and nanowires are grown from the plurality of nanoparticles. The catalyst layer has a thickness that increases in a first direction, and the plurality of nanoparticles have diameters that increase in the first direction.

Abstract: A terahertz radiation source includes: a cathode configured to emit an electron beam, an anode configured to focus the electron beam emitted from the cathode; a collector facing the cathode and configured to collect the emitted electron beam focused by the anode; an oscillating circuit positioned between the anode and the collector and configured to convert energy of a passing electron beam into electromagnetic wave energy; and an output unit connected to the oscillating circuit and configured to externally emit the electromagnetic wave energy.

Abstract: Provided are 3-dimensional standing type metamaterial structures and methods of fabricating the same. The 3-dimensional metamaterial structure includes a substrate; and a resonator, which includes a fixing unit fixed to the substrate; and a plurality of arms, which extend from the fixing unit and are curved upward on the substrate, wherein permittivity, permeability, and refractive index of the metamaterial structure in a predetermined frequency band differ from permittivity, permeability, and refractive index of the substrate. The resonator may be easily fabricated in MEMS/NEMS (micro-electro-mechanical system/nano-electro-mechanical system) processes.

Abstract: A solar cell includes a plurality of nanowires arranged such that diameters of the nanowires sequentially increase in a first direction along a path of incident light. In a method of forming nanowires, a catalyst layer is formed on a substrate, a plurality of nanoparticles are formed by thermally processing the catalyst layer, and nanowires are grown from the plurality of nanoparticles. The catalyst layer has a thickness that increases in a first direction, and the plurality of nanoparticles have diameters that increase in the first direction.

Abstract: Provided are a substrate structure and method of forming the same. The method of forming the substrate structure may include etching a substrate to form an etched portion having a vertical surface, forming a diffusion material layer on the whole substrate or in part of the substrate; annealing the diffusion material layer to form a seed layer diffused downward toward the surface of the etched portion, and forming a metal layer on the seed layer. Accordingly, surface characteristics of the etched portion of the substrate may be enhanced by the seed layer, and therefore, a metal layer with improved adhesion and a uniform thickness may be formed on the vertical surface of the etched portion.

Abstract: A method of multi-stage substrate etching and a terahertz oscillator manufactured by using the method are provided. The method comprises the steps of forming a first mask pattern on any one surface of a first substrate, forming a hole by etching the first substrate using the first mask pattern as an etching mask, bonding, to the first substrate, a second substrate having the same thickness as a depth to be etched, forming a second mask pattern on the second substrate bonded, forming a hole by etching the second substrate using the second mask pattern as an etching mask, and removing an oxide layer having the etching selectivity between the first substrate and the second substrate.

Abstract: Electromagnetic wave oscillators each having a multi-tunnel and electromagnetic wave generating apparatuses including the electromagnetic wave oscillators are provided. The electromagnetic wave oscillator includes: a first waveguide which has a folded structure such that a path traveled by an electromagnetic wave through the first waveguide crosses an axial direction a plurality of times; an electron beam tunnel through which an electron beam passes, wherein the electron beam tunnel extends along the axial direction and crosses the first waveguide a plurality of times; and at least one auxiliary tunnel which extends parallel to the electron beam tunnel and which crosses the first waveguide a plurality of times.

Abstract: A metamaterial structure is provided, including a substrate and a plurality of resonators that are provided on different surfaces of the substrate or different layers of the substrate. The resonators have resonance characteristics different from each other, and the metamaterial structure has a permittivity, a permeability, and a refractive index respectively different from those of the substrate in a predetermined frequency bandwidth.

Abstract: An electromagnetic wave transmission filter may include a substrate and one or more coils. The one or more coils may be at least partly disposed in an opening through the substrate. An electromagnetic camera may include an electromagnetic wave detector array, including a plurality of detector cells for detecting electromagnetic waves, and an electromagnetic wave transmission filter disposed in front of the electromagnetic wave detector array to provide each of the detector cells with an electromagnetic wave of a certain wavelength. The electromagnetic wave transmission filter may includes a substrate and a plurality of coils. At least one of the plurality of coils may be at least partly disposed in each of a plurality of openings through the substrate.

Abstract: A method of multi-stage substrate etching, includes forming a first mask pattern on one surface of a first substrate; forming a hole by etching the first substrate using the first mask pattern as an etching mask; forming a second mask pattern on one surface of a second substrate; forming a hole by etching the second substrate to a predetermined depth using the second mask pattern as an etching mask; bonding the first and second substrates together such that an etched surface of the first substrate faces an etched surface of the second substrate; forming a third mask pattern on the second substrate; and forming a hole passing through the second substrate by etching the second substrate using the third mask pattern as an etching mask, whereby it is prevented the occurrence of a radius of curvature in the bottom surface and the overhang structure occurring on a step surface.