40results about How to "Enhance radiative recombination" patented technology

The invention discloses an ultraviolet LED epitaxial structure, which comprises a substrate, a buffer layer, an n-type AlGaN layer, a multi-quantum well region, a composite structure region and a p-type GaN layer arranged in turn from bottom to top. The composite structure region is composed of an Al<x>Ga<1-x>N concave layer, a p-type Al<y>Ga<1-y>N electron barrier layer and a p-type Al<z>Ga<1-z>Nhole injection layer in turn from bottom to top. By adjusting the Al components of all parts of AlGaN of the composite structure region individually or jointly, the composite structure region obtained not only can reduce the electron leakage in the multi-quantum well region, but also can increase hole injection. The epitaxial structure provided by the invention can enhance radiation recombinationand improve the optical output power of ultraviolet LED.

The invention discloses an ultraviolet light-emitting diode with a p-i-n type multi-quantum well structure, which is sequentially arranged with a substrate, an AlN buffer layer, an n-type AlGaN layer, and a p-i-n type multi-quantum well Active region, electron blocking layer, p-type AlGaN layer, p-type GaN ohmic contact layer, n-type electrode arranged on n-type AlGaN layer, and p-type electrode arranged on p-type GaN ohmic contact layer. The ultraviolet light-emitting diode with p-i-n type multi-quantum well structure provided by the present invention can improve carrier concentration and injection efficiency, and can utilize the concentration difference of carriers in adjacent regions with different doping concentrations to form a The electric field with the opposite direction of the original built-in electric field can weaken the original built-in electric field between the p-type region and the n-type region, and reduce the quantum confinement Stark effect caused by the built-in polarization electric field, so that electrons and holes The radiative recombination efficiency is improved, and the luminous power of the ultraviolet light-emitting diode is enhanced.

The invention discloses a high-speed LED optical communication resonant quasi-switching modulator. The power supply unit is a voltage-limiting constant-current control unit, and the control unit is used to generate and output control signals to realize timing control; the power supply unit, inductance, resistance and current The source I1 is connected in series in sequence to form a loop; the anode of the LED is connected to the positive pole of the power supply unit, and the cathode is connected to the positive pole of the current source I2 through the switch K101; the cathode of the LED is connected to the positive pole of the current source I1; when the control unit sends a control signal to make the switch K101 turn on, the limit The voltage and constant current control unit supplies positive power to the LED to turn on the LED quickly; at the same time, the inductor stores energy; when the control unit sends a control signal and the switch K101 is turned off, the constant current drops, and the inductor generates a negative voltage. Reverse power supply to the LED during the falling time, so that the LED light intensity drops rapidly. The invention has fast switch and good optical communication effect.

The invention discloses a high-speed LED optical communication modulator. The high-speed LED optical communication modulator comprises a control unit and a variable power supply unit; the variable power supply unit is an energy supply unit capable of switching in the positive and negative directions; the control unit generates switching and sequential control signals so that the variable power supply unit is driven to supply power to an LED; the sequential control signals are used for reducing the bending of an energy band via sequential control so that radiative recombination of carriers is improved; when the variable power supply supplies power in the positive direction, the LED is turned on, and the carriers are over-injected; and when the variable power supply supplies power in the reverse direction, the LED is turned off, and the carriers are injected in a reverse manner. The high-speed LED optical communication modulator also comprises a discharge circuit used for further accelerating the turn-off. According to the high-speed LED optical communication modulator, the over-injection of the carriers during turn-on and reverse injection of the carriers during turn-off are controlled so that the recombination rate of the carriers is increased, and the switching speed is greatly increased; the turn-off is further accelerated via the auxiliary discharge circuit; and the bending of the energy band is reduced via sequential control, and the radiative recombination of the carriers is improved.

The invention discloses a quantum dot solid film and a preparation method thereof. The method comprises the steps of: providing an initial quantum dot solid film; immersing the initial quantum dot solid film in an inorganic salt solution to carry out a ligand exchange reaction, annealing to obtain a Ligand-exchanged quantum dot solid film: coating the metal amine complex solution on the ligand-exchanged quantum dot solid film and annealing to obtain the quantum dot solid film. The quantum dot solid film prepared by the above method in the present invention not only effectively enhances the transmission and radiative recombination of charges (electrons and holes) between the quantum dot solid film layers, but also does not cause similar organic Changes in the solid-state film of quantum dots caused by the shedding of molecules from the surface of quantum dots, such as cracks caused by close packing, affect the performance of the device, thereby further improving the stability and life of the device.

The invention discloses a method and a device for detecting the effect of ultraviolet radiation on killing bacteria. The method comprises the following steps: firstly, obtaining the relationship between the ultraviolet radiation intensity, the ultraviolet radiation time and the bacteria killing rate; then, detecting the ultraviolet radiation intensity; Third, according to the ultraviolet irradiation intensity and the set irradiation time, the killing rate of bacteria is obtained. The device includes an ultraviolet intensity detection device, a time setting device and a sterilization rate calculation module. The invention can ensure the effectiveness of ultraviolet disinfection equipment to kill bacteria, especially Staphylococcus aureus, so that the sterilization process that cannot observe the effect originally has evaluation standards and control means, and can also avoid continued consumption after all Staphylococcus aureus is killed Energy, increasing the practicability of ultraviolet disinfection equipment.

The disclosure provides a light-emitting diode epitaxial wafer and a manufacturing method thereof, which belong to the technical field of semiconductors. The active layer of the light-emitting diode epitaxial wafer includes a plurality of alternately grown quantum well layers and quantum barrier layers, and each quantum well layer is made of Al z Ga 1‑z N layer, the multiple quantum barrier layers include multiple first-type quantum barrier layers close to the N-type layer and multiple second-type quantum barrier layers close to the P-type layer, the first type of quantum barrier layer is Al m Ga 1‑m N layer, z<m, the second type of quantum barrier layer includes the first sublayer, the second sublayer and the third sublayer stacked in sequence, the first sublayer is Al x Ga 1‑x N layer, the second sublayer is Al y Ga 1‑y N layer, z<x<y, and the third sublayer is an AlN layer. The use of the light-emitting diode epitaxial wafer can improve the carrier confinement ability of the quantum barrier layer, so that more carriers can recombine in the quantum well layer, thereby improving the internal quantum luminous efficiency of the light-emitting diode.