12 results about "Carrier capture" patented technology

The application provides a kind of green phosphorescent dopant material and its preparation method, organic electroluminescent device and organic electroluminescent device, the structural general formula of the green phosphorescent dopant material is chemical formula I, the green phosphorescent dopant material of the application introduces the OCN four-tooth ligand structure containing platinum, can effectively improve the stability of compound, further connects silane group on the parent core, the group has huge steric hindrance, hinders the close approach between Pt complex core plane, effectively weakens intermolecular pi-pi stacking effect, significantly reduces concentration quenching effect, more helps to improve carrier capture efficiency, improves device efficiency.The material of the application can obtain the device with higher luminous efficiency and longer service life while maintaining low driving voltage.

The application discloses a gas recognition visual-olfactory fusion optoelectronic synapse device and a preparation method thereof, and belongs to the technical field of semiconductor devices. The optoelectronic synapse device comprises a substrate, a two-dimensional material floating gate heterojunction and source and drain electrodes. The heterojunction at least comprises a channel layer and a floating gate layer stacked thereon, and forms a Type-II energy band structure, and the interface has a defect state for carrier capture and release. The channel layer generates photo-generated carriers in response to light pulses, and the floating gate layer responds to gas stimulation and changes the charge state through gas adsorption / desorption; by applying a programmable light pulse stimulus to the channel layer, the adsorption or desorption process of gas molecules on the floating gate layer and the charge state thereof are dynamically modulated, a dynamic electrical response signal fusing visual and olfactory information is output, and gas recognition is realized. The application significantly improves the gas recognition accuracy from 52.24% of a single mode to 98.27% by using a dual-mode fusion feature, and realizes the synergy of miniaturization, low power consumption and high-precision perception.

The application provides a semiconductor structure manufacturing method, and is applied to the technical field of semiconductors. In the application, a charge induction layer, such as aluminum oxide, is formed on the back surface of a semiconductor substrate, such as a silicon substrate, and then a field effect passivation layer is formed on the charge induction layer. Due to the high negative charge effect of aluminum oxide, the negative fixed charge of aluminum oxide can guide the ordered accumulation and neutralization of holes at the holes on the damaged silicon surface, reduce the random recombination of holes and electrons, thereby inhibiting the fluctuation of dark current, and finally improving the RTS noise. Secondly, due to the low defect density of aluminum oxide, the probability of carrier capture or release by interface defects and / or bulk defects can be reduced, random current fluctuation can be avoided, and the RTS noise amplitude can be directly reduced. Furthermore, due to the good thermal stability of aluminum oxide, the material structure and electrical properties thereof do not deteriorate within the working temperature range of the device, and the long-term noise suppression effect and dark current stability can be ensured.

A two-dimensional organic / inorganic heterojunction photodetector and a preparation method thereof belongs to the technical field of photoelectric devices. A few layers of two-dimensional materials are transferred to a substrate as a base material by a mechanical peeling method. A few layers of two-dimensional alloy materials are transferred to one side of the two-dimensional materials on the base material by polydimethylsiloxane (PDMS). Then, the base material is put into a tube furnace. A single organic molecular layer is epitaxially grown on the two-dimensional alloy material by controlling the heating temperature and time to form a heterojunction. Finally, a gold thin film is transferred to the organic molecular layer, so that a photodetector is manufactured. The heterojunctions formed by Van der Waals have fewer defects, which can enhance light absorption without causing carrier capture, enabling photodetectors possesses excellent detection capability, large light absorption, and enhanced photoconductivity.

The application discloses a semiconductor laser, comprising: a substrate, a lower limiting layer, a lower waveguide layer, an active layer, an upper waveguide layer, an electron blocking layer and an upper limiting layer arranged in sequence from bottom to top; the active layer comprises a well layer and a barrier layer; the lattice constant of the well layer is greater than or equal to the lattice constant of the barrier layer; the thermal expansion coefficient of the well layer is less than or equal to the thermal expansion coefficient of the barrier layer; and the elastic coefficient of the well layer is less than or equal to the elastic coefficient of the barrier layer. By designing the lattice constant of the well layer to be greater than or equal to the lattice constant of the barrier layer, the thermal expansion coefficient of the well layer to be less than or equal to the thermal expansion coefficient of the barrier layer and the elastic coefficient of the well layer to be less than or equal to the elastic coefficient of the barrier layer, the carrier capture effect, the deep level defect and the insulating interface of the depletion region of the active layer of the semiconductor laser can be effectively controlled, the symmetry breaking of the laser principle equilibrium state phase transition can be inhibited, and thus the sudden change phenomenon of the laser at the threshold can be effectively solved, and problems such as the conductance up-jump, the capacitance down-dip and the junction voltage up-jump can be eliminated.

The invention discloses a light-emitting diode epitaxial wafer with a double-gradient electron limiting layer and a preparation method of the light-emitting diode epitaxial wafer. According to the epitaxial wafer, an electron limiting layer composed of three n-type AlGaN sub-layers is arranged between an n-type GaN layer and an active layer. The average Al component and Si doping concentration between the sub-layers are increased in a stepped manner, and the Al component and the Si in each sub-layer are increased in a continuous gradient manner along the growth direction. According to the invention, the Al component gradient is utilized to construct an electron deceleration barrier, the electron drift speed is reduced, and the carrier capture probability is improved; the Si concentration gradient is matched to compensate the resistivity rise and the DX center effect caused by the high Al component, the increase of the working voltage is avoided, meanwhile, the structure can induce dislocation bending, and the crystal quality of the epitaxial layer is remarkably improved.

The invention discloses a visual-olfactory fused photoelectric synapse device for gas recognition and a preparation method thereof, and belongs to the technical field of semiconductor devices. The photoelectric synapse device comprises a substrate, a two-dimensional material floating gate heterojunction, a source electrode and a drain electrode, the heterojunction at least comprises a channel layer and a floating gate layer stacked on the channel layer, a Type-II energy band structure is formed, and an interface has a defect state for carrier capture and release. The channel layer responds to light pulses to generate photon-generated carriers, and the floating gate layer responds to gas stimulation and changes the charge state through gas adsorption / desorption; programmable light pulse stimulation is applied to the channel layer, the adsorption or desorption process and the charge state of gas molecules on the floating gate layer are dynamically modulated, a dynamic electrical response signal fusing visual and olfactory information is output, and gas recognition is achieved. According to the invention, the dual-mode fusion feature is utilized to significantly improve the gas recognition accuracy from 52.24% of a single mode to 98.27%, and the cooperation of miniaturization, low power consumption and high-precision sensing is realized.

The application provides an avalanche photodetector and a preparation method thereof, and relates to the technical fields of photodetectors and photoelectronic materials. The avalanche photodetector comprises, from bottom to top, an InP substrate, a first ohmic contact layer, a buffer layer, a multiplication layer, a charge control layer, a gradient layer, an absorption layer, a second ohmic contact layer and a cladding layer. The multiplication layer is made of AlGaAsSb. The gradient layer is made of Al with gradually changed components and In with unchanged components. The absorption layer is made of InGaAs and GaAs which are alternately and periodically grown. x Al y Ga 1‑x‑y As x Ga 1‑x As and GaAs y Sb 1‑y The application can realize short-wave infrared detection with expanded wavelength and high signal-to-noise ratio, effectively reduce carrier capture caused by band gap difference, reduce lattice strain at the interface, thereby reduce defect density, optimize the injection efficiency of carriers from the absorption layer to the multiplication layer, and thus improve the performance of the device.

The invention relates to the technical field of communication, and discloses a QAM (Quadrature Amplitude Modulation) carrier recovery method based on constellation module value estimation, which comprises the following steps of: preprocessing an actually input QAM complex signal to obtain module value data and a curve corresponding to the module value data, detecting to obtain a first maximum module value and a maximum module value sequence of an actual signal constellation, comparing the first maximum module value with a reference module value of a standard QAM signal constellation obtained under an ideal condition, and adjusting the power of the signal to obtain a power-adjusted signal; according to the maximum module value sequence of the actual signal constellation, obtaining a judgment threshold module value, forming a carrier recovery loop, enabling the carrier recovery loop to work in a carrier capture mode, and synchronously outputting a signal after carrier recovery; monitoring and judging the standard deviation corresponding to the phase discrimination output signal to realize the switching of the working mode of the carrier recovery loop; and enabling the carrier recovery loop to work in a carrier tracking mode, and synchronously outputting a signal after carrier recovery. According to the invention, the convergence speed of carrier recovery is improved, and the carrier synchronization precision is ensured.

The invention discloses a 2-micron waveband indium arsenide / indium phosphide quantum dot laser active region structure and a preparation method thereof. Comprising the steps of providing an indium phosphide substrate and performing high-temperature treatment on the surface; sequentially and epitaxially growing an indium-aluminum-arsenic layer matched with an indium phosphide lattice, an indium-aluminum-gallium-arsenic layer and an indium-gallium-arsenic layer serving as a quantum dot growth substrate layer; growing a multi-period quantum dot active layer on the substrate, wherein each period comprises an indium arsenide quantum dot layer, an indium gallium arsenic layer, an indium aluminum gallium arsenic layer and an indium gallium arsenic layer; and finally, sequentially growing an indium aluminum gallium arsenic layer, an indium aluminum arsenic layer, an indium phosphide light limiting layer and an indium gallium arsenic contact layer at the upper part. By adopting indium gallium arsenic as a quantum dot growth substrate and combining a quantum dot embedded quantum well structure, the light-emitting wavelength of the quantum dot is red-shifted to a 2-micron wave band; the carrier capture efficiency is improved through the energy band gradient, and the lasing efficiency is enhanced; and uniform nucleation of quantum dots is promoted by using an indium gallium arsenic growth interface, formation of quantum short lines is inhibited, and a reliable basis is provided for preparation of a 2-micron waveband quantum dot laser.

The application belongs to the technical field of organic electroluminescent materials, and particularly relates to an organic electroluminescent device, which synchronously greatly improves the luminous efficiency and service life of the organic electroluminescent device through deuterium modification of the structure of a compound and optimization of the collocation between a sensitizer and a guest. In terms of efficiency, the guest and the sensitizer have similarity due to structural homology, can form a uniform film, and lay a stable foundation for energy transfer; the guest and the sensitizer adjust the energy level difference through structural difference, realize efficient carrier capture and directional transfer, thereby inhibiting non-radiative transition, reducing exciton energy dissipation, significantly improving the fluorescent quantum yield, and guaranteeing efficient light emission. In terms of life, the high bond energy of the C-D bond effectively inhibits molecular cleavage, reduces material loss from the root, and the moderate deuteration of the sensitizer can further optimize the transmission stability inside the device, thereby greatly prolonging the long-term service life of the device.

The invention relates to a light-emitting sensitive transistor intelligent heat sensor based on a quantum well hot electron emission effect and an MOCVD preparation and micro-nano processing method thereof, and belongs to the technical field of semiconductor sensing. According to the sensor, a stepped or array type quantum well structure is embedded in a III-V group heterojunction bipolar transistor base region. The core is that the collector current and the current gain of the device are abnormally increased along with the temperature rise by utilizing the capture of a quantum well on current carriers and the hot electron emission effect of the quantum well along with the temperature change, so that the ultrahigh thermal sensitivity is realized. Two transistors of this kind are cascaded into a Darlington pair, and thermal response signals are significantly amplified. The invention also provides a correction charge control model which is used for optimizing key parameters such as quantum well width and the like so as to balance sensitivity and linearity. The device has electrical and optical output, the sensitivity is obviously higher than that of a traditional sensor, the preparation process is compatible with the existing photoelectric integration technology, and an innovative solution is provided for high-precision intelligent temperature measurement.