8 results about "Electron hole recombination" patented technology

The application provides a LED chip with reverse polarity and small hole light emission and a manufacturing method thereof. The epitaxial layer of the LED chip comprises a P-type window layer and an MQW light emitting layer. The doping concentration of a first region in the P-type window layer is greater than that of a second region, which can limit current expansion and improve light emitting efficiency. An ODR dielectric film layer and an ODR metal reflection layer form an ODR mirror at the bottom of the epitaxial layer. An insulating passivation layer and an N electrode on the sidewall of the epitaxial layer can form an ODR mirror on the sidewall of the epitaxial layer. The N electrode also has a first hollow region. The ODR mirror can be used to reflect light, so that the light emitted by the MQW light emitting layer is only emitted from the first hollow region, and stray light emitted by the sidewall is suppressed. In addition, the orthographic projection of the first hollow region in the first direction completely covers the P ohmic contact metal unit, so that the electron hole recombination region is located in the MQW light emitting layer under the orthographic projection of the first hollow region, and the light emitting efficiency is further improved.

This invention relates to a composite photocatalytic material with optimized electron transport pathways, its preparation method, and its applications. The purpose of this invention is to address the problems of high electron-hole recombination rates and difficulty in efficiently removing recalcitrant organic matter from water using existing photocatalytic technologies. The composite photocatalytic material with optimized electron transport pathways includes an active component and an electron-accepting platform coupled thereto, forming a stable interfacial contact structure between the active component and the electron-accepting platform. The active component is bismuth oxyiodide; the electron-accepting platform is Magnéli phase titanium suboxide. The composite photocatalytic material prepared by this invention can achieve highly efficient photocatalytic oxidation removal of organic pollutants without the addition of external chemical reagents, and is particularly suitable for the treatment of antibiotics, pharmaceuticals, and other recalcitrant organic matter. This invention enhances the oxidation process by constructing an electron-accepting platform, offering advantages such as environmental friendliness, high carrier utilization efficiency, and wide applicability.

A doped (ultra-)wide bandgap ((U)WBG) semiconductor can demonstrate photoconductivity when illuminated with sub-bandgap light. Forming a rectifying semiconductor-metal junction on a suitably doped (U)WBG semiconductor enables a photoconductive semiconductor switch (PCSS) actuated by visible light with strong photoresponsivity and fast operation. A PCSS realized in Ge-doped AlN achieves an on / off ratio over one million, and a photoresponsivity of 2.8 A / W under sub-bandgap illumination at center wavelength 455 nm and power density as low as 1 mW / cm2. The PCSS can be turned off in under a second with a bias pulse that accelerates electron-hole recombination in the rectifying junction, quenching persistent photoconductivity. It also enables a semiconductor photodetector can measure very bright light without saturation or damage, and at elevated temperature. Such a photodetector realized in Ge-doped AlN demonstrates linear, non-saturating photoresponse for visible illumination power density up to ≥10.8 W / cm2 and operating temperature up to ≥200° C.

This invention discloses an experimental method for measuring the electron-hole recombination emission rate. The apparatus for this method includes a laser chip (with an anti-reflection coating on only one end of its horizontal two-sided end face), a plano-convex lens, a polarizer, a fiber optic coupler, an optical fiber, and a spectrometer. The plano-convex lens, polarizer, plano-convex lens, and fiber optic coupler are placed sequentially on the same horizontal line on both sides of the chip. The fiber optic coupler is connected to the spectrometer via an optical fiber. First, energy is applied to the laser chip, causing it to emit light from both sides. The spectra from both sides are focused onto the fiber optic coupler by the plano-convex lens and then transmitted to the spectrometer via the optical fiber. By rotating the polarizer, different polarization spectra can be selected to obtain specific spectral images under transverse electric / magnetic field modes. Finally, by substituting the spectral data from both ends into the established formula, the electron-hole recombination rate of the laser chip can be calculated.

This invention discloses a method for preparing TCPP / Emodin composite photocatalysts and their antibacterial applications, belonging to the field of pharmaceutical antibacterial medicine. Addressing the issues of drug resistance easily induced by traditional antibiotics in treating bacterial infections, performance defects in existing photocatalysts, and insufficient antibacterial capacity of single antibacterial materials, this invention leverages the advantages of tetracarboxyphenylporphyrin (TCPP)—strong visible light capture ability and low photogenerated electron-hole recombination rate—and complements emodin's π-conjugated system and its structural advantage of promoting carrier migration. The two are covalently linked through a chemical coupling mechanism involving EDC / NHS synergistic activation of the carboxyl group. Through steps such as dissolution, mixing reaction, dialysis purification, and freeze-drying, spherical TCPP / Emodin composite nanomaterials with a particle size of 100-500 nm are obtained. This composite material reduces the photogenerated electron-hole recombination rate and improves carrier migration efficiency, efficiently generating ROS under visible light irradiation, and exhibits excellent photodynamic antibacterial properties.

The disclosure relates to a III-nitride semiconductor light emitting device comprising: a first semiconductor region having a first conductivity; a second semiconductor region having a second conductivity different from the first conductivity; and an active region interposed between the first and second semiconductor regions and generating light through electron-hole recombination wherein the active region includes a quantum well layer with an indium (In) content (x) corresponding to an emission wavelength below 500 nm and emits light with a wavelength exceeding 600 nm.