44 results about "Density of states" patented technology

A variable semiconductor all-optical buffer and method of fabrication is provided where buffering is achieved by slowing down the optical signal using a control light source to vary the dispersion characteristic of the medium based on electromagnetically induced transparency (EIT). Photonic bandgap engineering in conjunction with strained quantum wells (QWs) and quantum dots (QDs) achieves room temperature operation of EIT. Photonic crystals are used to sharpen the spectral linewidths in a quantum well structure due to its density of states and in a quantum-dot structure caused by the inhomogeneity of the dot size, typically observed in state-of-the-art QD materials. The configuration facilitates monolithic integration of an optical buffer with an amplifier and control laser to provide advantages over other material systems as candidates for optical buffers.

The invention provides a structure design of tunnel junction in Perovskite / silicon heterojunction lamination solar battery, which relates to the field of solar batteries. A tunneling composite layer TRL with narrow band gap and high doping concentration is added at the junction of the top and bottom part of a lamination battery, and the quite small energy level difference between the conduction band and the valence band can effectively strengthen the carrier recombination at the tunneling junction. The gradient band order at the bottom battery p layer and the tunneling junction can effectivelyenhance the cavity draw-off of the bottom battery and the tunneling junction, and thereby a large amount of charge accumulation among the tunneling junction interfaces can be prevented. After the adding of the TRL having high doping concentration, the defect density of states at the tunneling junction is increased. The electronic cavity assists tunneling through defects, and the probability of recombination and tunneling can be increased. With the adoption of the heterojunction, the spectrum response of the bottom battery can be effectively enhanced, and the opening and pressing loss can be reduced. The preparation method is simple and easy to carry out.

The embodiment of the invention provides a simulation method and device for predicting lithium-ion battery material electrochemical performance and equipment. The simulation method comprises the stepsthat basic crystal structure parameters of an electrode material of a battery are acquired, and a crystal structure model of the electrode material is constructed; the crystal structure model is optimized, and optimal crystal structure parameters with minimum total energy are obtained; an optimal crystal is constructed according to the optimal crystal structure parameters; energy band calculationis performed on the optimal crystal, and an energy band, density of states and dynamic parameters of the optimal crystal are acquired; phonon spectrum calculation is performed on the optimal crystal,and thermodynamic parameters of the optimal crystal are acquired; a synthetic electrode material with the optimal crystal structure parameters is synthesized; the synthetic electrode material is adopted to construct a battery sample model, and dimension parameters of the battery are acquired; charge-discharge loop testing, battery surface temperature distribution testing and temperature rise curve testing are performed on the battery; an electrochemical-thermal coupling model of the battery is constructed; and the effectiveness of the electrochemical-thermal coupling model is verified.

The invention discloses a biological / chemical sensor on the basis of organic thin-film transistors. The biological / chemical sensor comprises a substrate, a first gate electrode, a first gate insulating layer, source / drain electrodes, an organic semiconductor layer, a second gate insulating layer, a second gate electrode, a sensitive film and encapsulation layers which are sequentially laminated on one another from bottom to top. A bottom gate transistor which is arranged at the bottom of the biological / chemical sensor is formed by the first gate electrode, the first gate insulating layer, the source / drain electrodes and the organic semiconductor layer and is used as a reference device, a top gate transistor which is arranged on the top of the biological / chemical sensor is formed by the source / drain electrodes, the organic semiconductor layer, the second gate insulating layer and the second gate electrode and is used as a sensitive device, the organic thin-film transistors which are of low-voltage double-gate structures are formed by the top gate transistor and the bottom gate transistor, the top gate transistor and the bottom gate transistor have gate capacitance values which are greatly different from one another, and the organic semiconductor layer has low sub-gap density of states. The biological / chemical sensor has the advantages of low working voltage and cost, high sensitivity, detection target diversity and the like. Besides, the biological / chemical sensor is compatible to large-area high-speed printing / coating preparation processes, can be used for manufacturing wearable or mobile sensors and has a broad application prospect in the field of health monitoring and healthcare medical treatment.

A variable semiconductor all-optical buffer and method of fabrication is provided where buffering is achieved by slowing down the optical signal using a control light source to vary the dispersion characteristic of the medium based on electromagnetically induced transparency (EIT). Photonic bandgap engineering in conjunction with strained quantum wells (QWs) and quantum dots (QDs) achieves room temperature operation of EIT. Photonic crystals are used to sharpen the spectral linewidths in a quantum well structure due to its density of states and in a quantum-dot structure caused by the inhomogeneity of the dot size, typically observed in state-of-the-art QD materials. The configuration facilitates monolithic integration of an optical buffer with an amplifier and control laser to provide advantages over other material systems as candidates for optical buffers.

A method of predicting photostability of coatings with various dopants on titanium dioxide pigment particles is disclosed. Calculations of the density of states show that a doped coating which reduces the density of states near the band edge or increases the density of states within the band gap of the pigment particles increases the photostability of the doped pigment.

An optical amplifier having a uniform gain profile uses a photonic crystal to tune the density-of-states of a gain medium so as to modify the light emission rate between atomic states. The density-of-states of the gain medium is tuned by selecting the size, shape, dielectric constant, and spacing of a plurality of microcavity defects in the photonic crystal. The optical amplifier is particularly useful for the regeneration of DWDM signals in long optical fibers.

The invention belongs to the micro nano manufacture technical field, and discloses a full-inorganic perovskite solar energy cell comprising a substrate glass, an ITO conductive layer and a photoanode, a luminous absorption layer and a carbon counter electrode layer; the photoanode is a CdS nanorod array structure having aperture structures; the luminous absorption layer is a CsPbBr3 inorganic perovskite layer embedded in the aperture structures of the photoanode, thus tightly contacting with the photoanode; the carbon counter electrode layer is paved on the top surface of the ITO conductive layer and the top surface of the luminous absorption layer, and formed by screen printing films. The contact areas between the perovskite layer and an electron transmission layer can be obviously improved, thus increasing the charge transmission channels; UV ozone processing is carried out for the grown CdS nanorod array, thus obviously improving the CdS film interface characteristics, reducing crystal grain boundaries, reducing electron defect density of states, reducing unfavorable charge recombination, and improving the electron transmission characteristics.

A method for controlling a structure of a nano-scale substance, which comprises irradiating a mixture of low-dimensional quantum structures having a nano-scale with an electromagnetic wave in an oxygen atmosphere, to thereby selectively oxidize a low-dimensional quantum structure having a density of states resonating with the electromagnetic wave used for the irradiation. The method allows a low-dimensional quantum structure having a specific structure to be selectively disappeared from the mixture of low-dimensional quantum structures having a nano-scale.

Present invention relates to porous silica luminescence device, belonging to optoelectronics technique field. It features utilizing surface plasma wave Purcell effect enhancing porous silica luminescence. It contains forming surface plasmaguide on porous silica layer, porous silica emissive light coupling to surface plasmaguide- guided mode, then scattering to free air. Due to surface plasmaguide- guided mode density of states is very large, porous silica spontaneous radiation is greatly enhanced, therefore luminous efficiency raising greatly, this make the porous silica becoming the important material used in high efficiency silica-based support luminescence device, and capable of being used in photoelectricity integrating and light interconnection.

A method of predicting photostability of coatings with various dopants on titanium dioxide pigment particles is disclosed. Calculations of the density of states show that a doped coating which reduces the density of states near the band edge or increases the density of states within the band gap of the pigment particles increases the photostability of the doped pigment.

The invention describes a detection device that comprise nanostructures and which detection mechanism is based on the quantum confinement effects. The analyte species are sensed by measuring charge or / and energy transfer between the species and the nanostructures, which will be proportional to the overlap between the density of states distribution in the nanostructures and the density of states distribution in the targeted analyte species.

A method of radiative cooling of optoelectronic devices using a hyperbolic metamaterial TIM layer below the heat generating optoelectronics is disclosed. Optoelectronic devices are optimized for high radiative heat conductance due to broad hyperbolic frequency band in the Long-Wavelength Infrared (LWIR) range with an efficient electromagnetic black hole thermal interface between the metamaterial TIM layer and a metallic heat sink. A modified Stefan-Boltzmann law in the hyperbolic metamaterial layer enables domination of the radiative heat transfer in the TIM layer. The broadband divergence of the photonic density of states in hyperbolic metamaterials leads to an increase in radiative heat transfer, beyond the limit set by the Stefan-Boltzmann law. The resulting radiative thermal hyper-conductivity approach or even exceed heat conductivity via electrons and phonons in regular solids.

A thin film semiconductor device comprises a substrate, a gate electrode disposed above the substrate, an oxide semiconductor layer disposed above the substrate so as to oppose the gate electrode, a channel protective layer disposed on the oxide semiconductor layer, and a source electrode and a drain electrode each connected to the oxide semiconductor layer. The density of states DOS [eV−1cm−3] of oxygen defects in the oxide semiconductor layer satisfies the following relationship:DOS≦1.710×1017×(Ec−E)2−6.468×1017×(Ec−E)+6.113×1017 provided that 2.0 eV≦Ec−E≦2.7 eVwhere Ec [eV] is an energy level of a conduction band edge of the oxide semiconductor layer and E [eV] is a predetermined energy level of the oxide semiconductor layer.

A light emitting photonic bandgap (PBG) material, and devices uses the same, having (a) a polymer network exhibiting a non-uniform pitch; (b) a small molecule liquid crystal material with a birefringence >0.04; and (c) one or more light emitting dyes having a low triplet state absorption. The light emitting PBG material has a defect-induced density of states enhancing feature at a wavelength that overlaps the emission spectrum of the light emitting dye. Excitation of the light emitting PBG material by a light source causes a directional electromagnetic emission from the light emitting material. The PBG material, and device, are capable of emitting continuous wave laser light as a result of excitation by a low-power incoherent light source.

A photodetector is formed from a body of semiconductor material substantially surrounded by dielectric surfaces. A passivation process is applied to at least one surface to reduce the rate of carrier generation and recombination on that surface. Photocurrent is read out from at least one electrical contact, which is formed on a doped region whose surface lies entirely on a passivated surface. Unwanted leakage current from un-passivated surfaces is reduced through one of the following methods. (a) The un-passivated surface is separated from the photo-collecting contact by at least two junctions (b) The un-passivated surface is doped to a very high level, at least equal to the conduction band or valence band density of states of the semiconductor (c) An accumulation or inversion layer is formed on the un-passivated surface by the application of an electric field. Electrical contacts are made to all doped regions, and bias is applied so that a reverse bias is maintained across all junctions.

The invention provides a transition metal chalcogenide nanowire and a preparation method and an application thereof. The preparation method comprises that under vacuum conditions, a metal, semi-metalor semiconductor substrate is kept to be heated to 250 DEG C-350 DEG C, transition metal atoms and chalcogenide atoms are evaporated onto the substrate, a transition metal chalcogenide film is prepared, the transition metal chalcogenide film is heated and annealed, and thus the transition metal chalcogenide nanowire is prepared. The prepared nanowire has the advantages of regular shape, definite width, uniform distribution of density of states, no impurity ions, simple operation and high preparation efficiency, and can be used for studying quantum physical phenomena in one-dimensional systems,wires in nanoscale circuits, and metal-monatomic layer semiconductor contact.

Systems, apparatuses, and methods for modulating light at high frequencies by addressing the issue of direct modulation of long lifetime light emitters. Dynamic control of the local density of optical states (LDOS) to exploit the differences between electric and magnetic dipole transitions allows for higher frequency modulation. The LDOS is controlled, in part, by designing a structure such that it enhances or suppresses electric and magnetic dipoles. Direct modulation may be achieved by designing the optical environment to adjust the interferences between the emitted light field and its own reflection at the emitter's location. The optical environment may include light emission material, switchable material, spacer materials, and reflective materials. The structures creating the optical environment enable a new nanometer-scale architecture for on-chip ultrafast directly modulated light sources, which could be easily integrated locally on a range of nanoelectronic and nanophotonic structures, along with light-emitting diodes, waveguides, and fiber optics.

The invention discloses a Gallium nitride based high electron mobility transistor epitaxial structure and a manufacturing method thereof. The epitaxial structure comprises a substrate layer on which an AlN nucleating layer, an AlGaN buffer layer, an Al doped GaN template layer and an AlGaN barrier layer grow from bottom to top. Since a method of forming GaN template layer through Al doping is adopted during the process of manufacturing the Gallium nitride based high electron mobility transistor epitaxial structure, the dislocation density of material can be reduced, flatness of a plane can be improved, the electron mobility of the material can be enhanced, the density of states of the surface of heteroepitaxy AlGaN buffer layer can be reduced, the leak current of a device can be lowered further and the breakdown voltage of the device can be improved; in addition, the process is simple and flexible.

A method of predicting photostability of coatings with various dopants on titanium dioxide pigment particles is disclosed. Calculations of the density of states show that a doped coating which reduces the density of states near the band edge or increases the density of states within the band gap of the pigment particles increases the photostability of the doped pigment.

The invention discloses a TVS device chip in the technical field of TVS devices. The TVS device chip comprises a package casing, a TVS chip layer, an overcurrent chip layer, a first pin and a second pin. The inner cavity of the package casing is provided with the TVS chip layer and the overcurrent chip layer, the bottom of the TVS chip layer is connected to one end of the first pin by a wire, andthe top of the overcurrent chip layer is connected to one end of the second pin through a wire. Through the novel design of two chips in a TVS, one chip can satisfy a transient voltage clamp protection function, the other chip is automatically disconnected when over-current is continuous, through a high-molecular polymer in a reset over-current filler, when power-off and fault are removed, the collection temperature is reduced, the density of states is increased, the phase transition recovers, nanocrystals are reduced to a chain-like conductive path, the TVS device is restored to a normal state, therefore, the circuit is not short-circuited, and the fire of a circuit is not caused.

The invention discloses a method for calculating electric conductivity under intrinsic defect of monolayer graphene. The invention can be used to calculate the change of the structure and the electronic characteristic after the intrinsic defect occurs in the perfect graphene crystal cell structure, so as to obtain the change of the electric conductivity of the perfect graphene crystal cell. At first, that invention establishs a cell configuration model of each type of intrinsic defect of the monolayer graphene; Then the most stable unit cell constant of the defect structure is obtained by using the first principle. By comparing cell structures, static states and density of states of perfect the cell and perfect defect cells, the conductivity changes of graphene after intrinsic defects areanalyzed and deduced theoretically. The invention expands the experimental measurement based on the rigorous theoretical analysis means and is suitable for the extremely sensitive influence analysis of graphene defects on the conductivity thereof.

A volume-scalable, high-brightness, electrically driven visible light source comprises a three-dimensional photonic crystal (3DPC) comprising one or more direct bandgap semiconductors. The improved light emission performance of the invention is achieved based on the enhancement of radiative emission of light emitters placed inside a 3DPC due to the strong modification of the photonic density-of-states engendered by the 3DPC.

The invention provides a lighting device comprising (a) a light converter comprising a light receiving face; and (b) a solid state light source configured to generate a light source light with a photon flux of at least 10 W / cm2 at the light receiving face, wherein the light converter is configured to convert at least part of the light source light into light converter light having a first frequency, wherein the light converter comprises a semiconductor quantum dot in an optical structure selected from a photonic crystal structure and a plasmonic structure, wherein the optical structure is configured to increase the photon density of states in the light converter resonant with the first frequency for reducing saturation quenching, and wherein the quantum dot has a quantum efficiency of at least 80%.

Electrical conductance measurement system including a one-dimensional semiconducting channel, with electrical conductance sensitive to electrostatic fluctuations, in a circuit for measuring channel electrical current. An electrically-conductive element is disposed at a location at which the element is capacitively coupled to the channel; a midpoint of the element aligned with about a midpoint of the channel, and connected to first and second electrically-conductive contact pads that are together in a circuit connected to apply a changing voltage across the element. The electrically-conductive contact pads are laterally spaced from the midpoint of the element by a distance of at least about three times a screening length of the element, given in SI units as (K∈0 / e2D(EF))1 / 2, where K is the static dielectric constant, ∈0 is the permittivity of free space, e is electron charge, and D(EF) is the density of states at the Fermi energy for the element.

The invention relates to the design and development research field of ternary boride cemented carbide, A method for screen transition metal doping element capable of improving hardness of cemented carbide is provided, By using the first principle simulation method based on density functional theory, Structural models of WCoB, MoCoB, Mo2FeB2, Mo2NiB2 were optimized, and different contents of transition metal elements were doped to optimize the structure. The structure parameters, mechanical properties and electronic structure before and after doping were analyzed, and the hardness model was used to calculate and analyze. By analyzing the structural parameters and using various hardness models, the variation trend of hardness is analyzed comprehensively. Using Origin software, valence bond theory and band theory to draw charge density diagram, density of states diagram and so on, analyze the trend of covalence change and hardness change. The invention provides direct theoretical guidancefor the material design of the ternary boride cemented carbide, shortens the research and development period and reduces the research and development cost.

A method, performed by an electronic device, of predicting an electronic structure of a material includes: receiving input data of a user related to elements constituting the first material; applying the received input data to a trained model for estimating a density of state of the first material; and outputting a first graph indicating the density of state for each energy level of the first material output from the trained model, wherein the trained model is trained to generate the first graph based on pre-input data about a plurality of second materials composed of at least some of the elements constituting the first material and a plurality of second graphs representing the density of state for each energy level of the plurality of second materials.