32 results about "Potential barrier height" patented technology

The invention relates to an LED structure comprising quantum barriers with gradient potential barrier heights and a method for manufacturing the LED structure, and belongs to the technical field of photoelectrons. The LED structure is provided with a plurality of quantum well layers, and the potential barrier heights of the quantum barriers are gradually reduced from an n side to a p side. Conveyance of electron holes is improved owing to the novel structure, so that the electron holes can be distributed in large quantities of quantum wells, and the intensity of polarization among the potential barriers is reduced in general. Owing to the factors, the distribution of the concentration of electrons and the distribution of the concentration of the electron holes are improved totally, the rate and the intensity of spontaneous radiation are increased totally, and accordingly, the internal quantum efficiency of a device is effectively enhanced, and outputted optical power of the device is effectively increased.

The invention discloses a quantum dot solid film with continuously changing barrier height and a preparation method thereof, wherein the quantum dot solid film includes N quantum dot thin film units sequentially arranged in the radial direction, wherein N≥3; The energy level barrier heights of the N quantum dot film units present a trend of continuous increase or decrease in the radial direction. The potential barrier height of the quantum dot solid film provided by the present invention can be continuously increased or decreased, thereby matching the potential barrier height of each transport layer; further, the quantum dot solid film can also effectively regulate the injection potential of electrons and holes barrier height, which is beneficial to the recombination of electrons and holes to improve device efficiency; therefore, the present invention effectively solves the problem that the cross-linking technology can only change the injection barrier between the quantum dot solid film and the transport layer interface, but cannot make the entire quantum dot The continuous increase or decrease of the barrier height of the dot solid film cannot effectively improve the recombination probability of electrons and holes.

The invention provides a germanium-silicon avalanche photodetector, comprising: an avalanche amplification region; a first ohmic contact layer and a charge collection region respectively in contact with the avalanche amplification region; a control gate structure connected to the charge collection region; Wherein, the control gate structure is used to control the barrier height of the charge collection region. That is to say, based on the control gate structure, the silicon germanium avalanche photodetector controls the barrier height of the charge collection region by adjusting the gate voltage, so that only the carrier accumulation potential energy in the dark current is higher than a certain potential barrier Only when it is allowed to pass through, the dark current of the germanium-silicon avalanche photodetector is reduced, and the photoelectric conversion efficiency is improved.

A process for manufacturing a thermoelectric material having a plurality of grains and grain boundaries. The process includes determining a material composition to be investigated for the thermoelectric material and then determining a range of values of grain size and / or grain boundary barrier height obtainable for the material composition using current state of the art manufacturing techniques. Thereafter, a range of figure of merit values for the material composition is determined as a function of the range of values of grain size and / or grain boundary barrier height. And finally, a thermoelectric material having the determined material composition and an average grain size and grain boundary barrier height corresponding to the maximum range of figure of merit values is manufactured.

The invention belongs to the technical field of a semiconductor and relates to a gate-ballast structure RF AlGaN / GaN HEMTs device and a preparation method thereof. The device includes a AlGaN / GaN substrate on SiC, a gate, a source and a drain, wherein the gate is a doped polysilicon, and square resistance is in a range of 20-40omega / sq. The doped polysilicon is taken as a gate, barrier potential height is high, a gate leakage is smaller compared with a conventional Ni / Au schottky gate, power consumption of a radio frequency power device is reduced, efficiency is improved, and the doped polysilicon has relatively low Rg and has the ballast resistor function. The device can be applied to a multi-finger gate device AlGaN / GaN HEMTs, through adjusting Lg length, the purpose of optimizing Wg length is achieved, heat radiation of the device is effectively improved, the device can be further applied to AlGaN / GaN HEMTs, and the polysilicon gate can be biased by wider Vgs swing.

The invention discloses an ultraviolet LED epitaxial sheet and its preparation method and application, wherein the ultraviolet LED epitaxial sheet includes an n-type semiconductor layer, an active layer, an electron blocking layer and a p-type semiconductor layer which are epitaxially grown in sequence; the electron blocking layer consists of a first The first sublayer and the second sublayer are alternately grown in a superlattice structure, the first sublayer is an aluminum boron nitride layer, and the second sublayer is an aluminum gallium nitride layer. The ultraviolet LED epitaxial wafer provided by the present invention uses alternately grown aluminum boron nitride layers and aluminum gallium nitride layers to form an electron blocking layer, so that the energy level position of the conduction band of the electron blocking layer is higher, and the effective barrier height of electrons is increased, effectively Block electrons from transitioning to the p-type semiconductor layer; at the same time, reduce the hole barrier height between the electron blocking layer and the active region, and significantly improve the injection efficiency of holes injected into the active layer; therefore, the radiative recombination rate of the active region can be increased, Thereby improving the luminous efficiency of the ultraviolet LED.

A process for manufacturing a thermoelectric material having a plurality of grains and grain boundaries. The process includes determining a material composition to be investigated for the thermoelectric material and then determining a range of values of grain size and / or grain boundary barrier height obtainable for the material composition using current state of the art manufacturing techniques. Thereafter, a range of figure of merit values for the material composition is determined as a function of the range of values of grain size and / or grain boundary barrier height. And finally, a thermoelectric material having the determined material composition and an average grain size and grain boundary barrier height corresponding to the maximum range of figure of merit values is manufactured.

The invention relates to a GaN-based lateral junction potential barrier Schottky diode and a preparation method thereof. The potential barrier Schottky diode comprises: a substrate layer, a nucleation layer, a buffer layer, an insertion layer, a potential A barrier layer and a passivation layer; a P injection region is arranged in the buffer layer, the insertion layer and the barrier layer, and is located at one end of the buffer layer, the insertion layer and the barrier layer, and the P injection region includes a number of P regions and a number of N regions, and The region between two adjacent P regions without P injection is the N region due to the existence of two-dimensional electron gas; the anode electrode is located on the upper surface of the P injection region; the cathode electrode is located on the upper surface of the barrier layer, and It is located at the end of the barrier layer away from the anode electrode. A local barrier Schottky diode and a method for making the same, by forming a comb-shaped lateral PN junction between the P injection region and the two-dimensional electron gas, effectively shielding the Schottky junction with a low barrier height and suppressing the Schottky barrier lowering effect And control the reverse leakage current, improve the breakdown voltage, while maintaining a low turn-on voltage.