123 results about "Band bending" patented technology

A compliant wheel includes a compliant band and a plurality of web spokes extending transversely across and inward from the reinforced compliant band for attachment to a hub. The compliant band bends to comply with a contact surface and to envelope obstacles. The web spokes transmit load forces between the compliant band and the hub through tension in the web spokes not connected to the ground contacting portion of the wheel. The outer surface of the compliant band may be formed to include a tread, or a separate tread band may be attached.

The present invention provides a thin film amorphous silicon-crystalline silicon back heterojunction and back surface field device configuration for a heterojunction solar cell. The configuration is attained by the formation of heterojunctions on the back surface of crystalline silicon at low temperatures. Low temperature fabrication allows for the application of low resolution lithography and/or shadow masking processes to produce the structures. The heterojunctions and interface passivation can be formed through a variety of material compositions and deposition processes, including appropriate surface restructing techniques. The configuration achieves separation of optimization requirements for light absorption and carrier generation at the front surface on which the light is incident, and in the bulk, and charge carrier collection at the back of the device. The shadowing losses are eliminated by positioning the electrical contacts at the back thereby removing them from the path of the incident light. Back contacts need optimization only for maximum charge carrier collection without bothering about shading losses. A range of elements/alloys may be used to effect band-bending. All of the above features result in a very high efficiency solar cell. The open circuit voltage of the back heterojunction device is higher than that of an all-crystalline device. The solar cell configurations are equally amenable to crystalline silicon wafer absorber as well as thin silicon layers formed by using a variety of fabrication processes. The configurations can be used for radiovoltaic and electron-voltaic energy conversion devices.

The invention provides an electron blocking layer structure of a photoelectric device. The electron blocking layer structure is characterized in that structure matching between a quantum well and a P layer is achieved through adjusting a lattice structure and a band gap as much as possible; meanwhile, the formation of a polarized electric field is reduced, the formation of a negative charge area in an electron blocking layer is weakened as much as possible, and further the efficiency is improved; the electron leakage caused by energy band bending of the electron blocking layer and the increment of hole potential energy of the P layer are weakened. The electron blocking layer structure of the photoelectric device adopts AlInGaN or AlInGaN/InGaN super-lattice structure growth, wherein the In component is less than or equal to 10 percent; the Al component is less than or equal to 40 percent; the gradual distribution of the In component and the Al component exists in the electron blocking layer, and gradual change principles of the In component and the Al component are mutually independent; as for the electron blocking layer with an AlInGaN/InGaN super-lattice structure, the gradual change of the In component occurs in a super-lattice AlInGaN or a super-lattice AlInGaN/InGaN or in both the super-lattice AlInGaN and the super-lattice AlInGaN/InGaN.

The invention discloses a GaN-based light-emitting diode epitaxial wafer and a manufacturing method of the GaN-based light-emitting diode epitaxial wafer, and belongs to the technical field of semiconductors. The GaN-based light-emitting diode epitaxial wafer comprises a substrate, a buffering layer, an undoped GaN layer, an n-type layer, a multiple-quantum-well layer and a p-type layer, wherein the multiple-quantum-well layer is of a multi-cycle structure, each cycle of the multiple-quantum-well layer comprises an InGaN quantum-well layer and a quantum barrier layer which grows on the InGaN quantum-well layer, each quantum barrier layer comprises a first InGaN layer, an AlGaN layer and a second InGaN layer, and each AlGaN layer and each second InGaN layer grow on each first InGaN layer in sequence. According to the scheme, the first InGaN layer and the second InGaN layer of each quantum barrier layer make contact with each InGaN quantum-well layer, the InGaN quantum-well layers, the first InGaN layers and the second InGaN layers are made of the same materials, the degree of lattice mismatch is low, produced stress is low, the effect of a piezoelectric polarization electric field is poor, the degree of band bending of the InGaN quantum-well layers and the quantum barrier layers becomes lower, the capacity of restraining charge carriers is improved, and when high current is injected, serious leakage current cannot be formed.

The invention relates to a semi-gate controlled source schottky barrier type tunneling field effect transistor. On the premise of no requirements on the introduction of a material such as a compound semiconductor, silicon germanide and germanium with a smaller forbidden bandwidth into the generation of a tunneling part of a device, a source schottky barrier is formed between a metal source and intrinsic silicon, and a semi-gate is used for controlling the barrier width of the source schottky barrier and the energy band bending degree of the intrinsic silicon to control the switching of the device. An asymmetrical semi-gate structural design is adopted, so that gate-induced drain leakage current is remarkably reduced on the premise of keeping gate voltage well controlling the width of the schottky barrier and the energy band bending degree. The semi-gate controlled source schottky barrier type tunneling field effect transistor has the advantages of process simplicity, low cost, high sub-threshold slope, high breakover current, low reverse leakage current and the like, and is suitable to be popularized and used.

The invention provides a gallium nitride-based light emitting diode with high luminous efficiency and a preparation method thereof, and belongs to the field of photoelectric device preparation. The LED can maintain higher photoelectric conversion efficiency and a lower Droop effect under bulk current injection. The LED comprises a bottom layer and a light emitting layer which are grown through an MOCVD technology and a P-type layer which is grown through a molecular beam epitaxy technology, namely, a gallium polar buffer layer, a non-doped nitride layer, an N-type nitride layer and a multiple-quantum-well light emitting layer are grown through the MOCVD technology, and then, a sample is transferred to the reaction chamber of molecular beam epitaxy equipment, and a nitrogen polar electron blocking layer, a P-type nitride layer and a P-type nitride contact layer are grown. Through the method, band bending caused by polarization between the electron blocking layer and the multiple-quantum-well light emitting layer is reduced, the barrier height of electron overshoot to the P-type layer is increased, and the barrier height of hole injection to the multiple-quantum-well region is reduced.

The invention belongs to the technical field of semiconductor devices, and particularly relates to a field-induced tunneling enhanced HEMT (high electron mobility transistor) device. The field-induced tunneling enhanced HEMT device is different from conventional AlGaN/GaN HEMT devices in that metal sources are in Schottky barrier contact instead of ohm contact in conventional structures; and metal gates are not positioned between the sources and drains but form insulating gate electrodes at the edges, away from the drains, of the sources through etching grooves. Field-control conductive channels are realized by means of the insulating layer and groove technology, field control of the field-control conductive channels is realized by voltage applied to the groove gate electrodes, and electrons subjected to band bending can directly tunnel barriers to be accumulated below the channels in gate modulation when forward voltage is applied to the gate electrodes, so that normally closed channels are realized, and frequency characteristics of the device can be promoted without affecting reverse voltage withstand capability of the device. Meanwhile, the preparation process of the device is compatible to traditional processes, and thereby solid foundation is established for the GaN power integration technology.

The invention provides a light-emitting diode epitaxial wafer and a preparation method thereof. The light-emitting diode epitaxial wafer comprises a substrate, and a buffer layer, a three-dimensional nucleating layer, a two-dimensional recovery layer, an undoped GaN layer, an N-type GaN layer, a multi-quantum well layer and a P-type layer which are sequentially stacked on the substrate, the multi-quantum well layer comprises x mixed polarity quantum well layers and quantum barrier layers which are periodically and alternately arranged; and the mixed polarity quantum well layer comprises y N polar surface quantum well layers and Ga polar surface quantum well layers which are periodically and alternately arranged. The quantum well solves the problem that the luminous efficiency of an LED epitaxial wafer is reduced due to energy band bending and inclination caused by a polarization electric field in an existing quantum well.

The invention provides a modulation method for luminous efficiency and intensity of a light-emitting diode. Through applying a stress to a light-emitting diode, a material of an N region and/or a P region of which are/is piezoelectric, the light-emitting diode is made deform and a piezoelectric field caused by the deformation modulates the luminous efficiency and intensity of the light-emitting diode. Correspondingly, the invention also provides the light-emitting diode. In the modulation method for the luminous efficiency and intensity of the light-emitting diode, through introducing an appropriate stress to the PN-junction light-emitting diode, the energy band of the light-emitting diode is adjusted so that current used for electro-optical conversion in the light-emitting diode is increased and at the same time band-energy bending is introduced near the PN junction. Electrons and cavity potential wells formed through the bending can attract and restrict carriers near the PN junction and increase and constraint of local electrons and cavity concentration make the electron and cavity composite efficiency increase so that internal quantum efficiency of the light-emitting diode is increased.

The invention discloses a light emitting diode epitaxial wafer and a manufacturing method of the light emitting diode epitaxial wafer and belongs to the technical field of semiconductors. The epitaxial wafer comprises a substrate, a buffer layer, an n-type layer, a multi-quantum well layer and a p-type layer, the buffer layer, the n-type layer, the multi-quantum well layer and the p-type layer are stacked on the substrate in sequence, the p-type layer is directly arranged on the multi-quantum well layer which comprises a first multi-quantum well layer and a second multi-quantum well layer, a plurality of InaGa1-aN quantum well layers and a plurality of quantum barrier layers are stacked alternately to form the first multi-quantum well layer, at least one of the quantum barrier layers is the AlxInyGa1-x-yN layer, wherein 0 <x <1, 0<= y <0.5. A plurality of InbGa1-bN quantum well layers and a plurality of quantum barrier layers are stacked alternately to form the second multi-quantum well layer, and a <=b. Due to the scheme, the defect concentration of the second multi-quantum well layer is reduced, barrier height is increased, buffering and intercepting abilities are improved, luminous efficiency of devices is increased, and the problems of lattice mismatch and band bending caused by an electron blocking layer are solved.

An optical waveguide, such as an optical fiber, including a core having a refractive index n_co and a radius r_co; an inner cladding laterally surrounding the core, the inner cladding having a refractive index n_ic and an outer radius of r_ic; an outer cladding laterally surrounding the inner cladding, the outer cladding having a refractive index n_oc; and a narrow depressed well, wherein n_co>n_oc>n_ic. The range of the ratio of the inner, depressed-well clad radius, r_ic, to core radius, r_co, varies from about 2.4 to 3.0. The waveguide has a +Δ of about 0.0014 to 0.0021, a −Δ of about −0.0021 to −0.0034, and a Δ_Tot of about 0.0043 to 0.0049.

The invention provides a new quantum well structure, which can further effectively increase the recombination probability of carrier, improve quantum efficiency and realize optimization and improvement of efficiency of a photoelectric device. AlInGaN is used as a barrier, an In and Al component gradual barrier layer structure is designed to substitute barrier layer structure design of the conventional quantum well structure. The In component is doped into the barrier layer structure of the quantum well, the band bending of the quantum well is reduced, a quantum confined stark effect is weakened, the electron blocking efficiency of an electron barrier layer is improved, a hole injection efficiency of the quantum well is increased, spatial wave function overlap of electrons and space is increased, and these have a positive effect on improvement of luminous efficiency of an LED (Light Emitting Diode); meanwhile the Al component is doped into the barrier layer structure of the quantum well, so migration of the electrons to a P layer is effectively blocked; through the gradual component design of the AlInGaN, the influence of a polarization electric field can be reduced, and the spontaneous emission spectrum strength of the quantum well is improved.

The invention belongs to the technical field of semiconductor devices, and particularly relates to a U-shaped channel tunneling transistor with a laminated structure and a preparation method thereof. According to the invention, a highly doped silicon layer of which the doping type is opposite to that of a SiGe source area is formed under the SiGe source area of the tunneling transistor by an epitaxial growth method; and the forbidden bandwidth of the SiGe is narrower than that of silicon, so that the band bending degree between the source area and a channel region can be improved, then the length of tunneling can be reduced and the tunneling efficiency is improved. The U-shaped channel tunneling transistor with the laminated structure which is provided by the invention can substantially improve firing current and reduces subthreshold swing under the circumstance that shutdown current is not influenced.

A method for fabricating a back-illuminated imager which has a pinned back surface is disclosed. A first insulator layer is formed overlying a mechanical substrate. A conductive layer is deposited overlying the first insulator layer. A second insulator layer is formed overlying the conductive layer to form a first structure, an interface being formed between the conductive layer and the second insulator layer, the conductive layer causing band bending proximal to the interface such that the interface is electrically pinned. Hydrogen is implanted in a separate device wafer to form a bubble layer. A final insulator layer is formed overlying the device wafer to form a second structure. The first structure and the second structure are bonded to form a combined wafer. A portion of the combined wafer is removed underlying the bubble layer to expose a seed layer comprising the semiconductor material substantially overlying the second insulator layer.

The invention discloses a treatment method for improving electrochemical performance of a composite catalyst. Illumination is applied to a B-site doped perovskite catalyst, the molecular formula of the B-site doped perovskite catalyst is AB1-yB'yO3, wherein A is selected from rare earth metal or alkaline earth metal, B is selected from transition metal or alkaline earth metal, B' represents a doping element and is the transition metal, A, B and B' are not equal to each other, and y is greater than 0 and is less than 1. The experiment shows that after an illumination condition is applied to theB-site doped perovskite catalyst doped with the transition element at the B site, when the concentration of photo-generated carriers in a perovskite material is large enough, a potential difference of a space charge layer can be greatly counteracted by the light voltage, so that band bending completely disappears, namely the space charge layer disappears. Namely the disappearance of the space charge layer is accelerated through the addition of the light, and the electrocatalytic reaction proceeds quickly; and the treatment method disclosed by the invention has a better application prospect inthe field of electrochemistry.

The invention discloses a light-emitting diode epitaxial structure containing a AlGaN conducting layer, and a manufacturing method thereof. The epitaxial structure is composed of a substrate, a GaN buffer layer, an N type GaN conductive layer, a multi-quantum-well active region and a P type AlGaN conducting layer. The P type conducting layer is made of analuminum-contained AlGaN material and Al components in the AlGaN layer are gradually increased linearly along the growth direction. Accoridng to the invention, with the P type AlGaN conducting layer, barriers for blocking injection of holes into the multi-quantum-well active region at the P type AlGaN electronic blocking layer and the P type GaN conducting layer can be avoided. Because the Al components in the P type AlGaN conducting layer are gradually increased along the growth direction, the polarized charge density, the polarized electric field intensity of the quantum well, and the band bending can be reduced, the electron overflowing blocking effect of the P type AlGaN conducting laywer can be enhanced, and the hole injection blocking can be weakened.

The invention provides a photocatalytic composite material with p-n heterojunction, and belongs to the field of organic pollutant treatment. The narrow-band-gap photocatalytic composite material withp-n heterojunction disclosed by the invention improves deficiency of a single catalyst, has a small band gap energy (1.87 eV), has a large absorption threshold on visible light, and has enhanced lightutilization efficiency. The p-n heterojunction caused by bending of the energy band increases the hole transfer ability, inhibits electron-hole recombination, improves the separation efficiency of photogenerated electrons and holes, prolongs the carrier lifetime and enhances the catalytic activity. Under visible light, the photocatalytic composite material has good degradation effects on organicpollutants in water, such as MO, MG, BPA, tetracycline hydrochloride, etc. At the same time, the narrow-band-gap photocatalytic composite material with p-n heterojunction disclosed by the invention can settle in water through standing, so that the narrow-band-gap photocatalytic composite material can be separated from an aqueous solution, and thus the narrow-band-gap photocatalytic composite material is beneficial to recovery and reuse of materials, has good regenerative capacity and can be recycled.

Corona charges are used to bias a wafer to push down mobile charges and then pull them up during temperature cycles. Mobile charge is measured from the drops in the corona voltage due to the mobile charges. Corrections are made in the measurements for dipole potentials, leakage and silicon band-bending.

Disclosed is a gallium nitride-based light emitting diode structure. The gallium nitride-based light emitting diode structure comprises a substrate, a bottom layer, an N type layer, a light emitting layer and a P type layer in sequence; the gallium nitride-based light emitting diode structure is characterized in that the P type layer consists of an electron barrier layer, at least one energy band deformation layer and a hole injection layer; the energy band deformation layer is inserted in the electron barrier layer or positioned between the electron barrier layer and the hole injection layer, or inserted in the hole injection layer or positioned on the hole injection layer; and the energy band deformation layer is a non-P type layer with carbon impurity content of not greater than 5*10<16>cm<-3>. By virtue of the low carbon impurity content, the energy band of the energy band deformation layer can be bent, and the two-dimensional hole gas concentration on a contact interface between the energy band deformation layer and the adjacent layer can be increased.

Enhanced band bending materials for use in rectifying contacts comprising metal nanoparticles and a semiconducting polymer that is soluble in common organic solvents including, for example, a gold-polymeric nanocomposite comprising gold nanoparticles in poly(m-phenylenevinylene-co-2,5-dioctoxy-p-phenlenevinylene( (“PmPV”). The nanocomposite material provides for enhanced Schottky barriers.