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

The invention provides a nitride light-emitting diode (LED) epitaxial wafer and a growing method thereof and relates to the technical field of semiconductor optoelectronics. The nitride LED epitaxial wafer structurally and sequentially comprises a substrate, a low-temperature buffer layer, an unintentionally doped GaN, an N-shaped electron-injection layer, an InGaN/GaN inserting layer, an active area, an electron blocking layer, a u-GaN/p-GaN superlattice and a p-GaN hole-injection layer from bottom to top. The InGaN/GaN inserting layer is grown between the N-shaped electron-injection layer and the active area so as to effective relieve stress of the active area, lower polarization electric fields, reduce limitation of stark effect through a quantum well, and improve luminance and anti-static properties. The u-GaN/p-GaN superlattice is inserted between the electron blocking layer and the P-shaped hole-injection layer so as to improve current expansion capacity and lower chip operating voltage.

A solid state light-emitting device comprising: a first electrode coupled to a first charge injecting layer; a second electrode coupled to a second charge injecting layer; an emissive layer comprising a perovskite material, wherein the emissive layer is provided between the first and second charge injecting layers; and wherein the bandgaps of the first and second charge injecting layers are larger than the bandgap of the emissive perovskite layer.

The invention provides a deep UV LED, which includes a substrate; an undoped buffer layer located on the surface of the substrate; an N type AlGaN layer on the undoped buffer layer and far away from the surface of the substrate; a multi-quantum well structure on the undoped buffer layer and far away from the surface of the substrate; and a P type AlGaN structure on the multi-quantum well structure and far away from the surface of the substrate, wherein the V type Al component of the P type AlGaN structure is gradually changed. The P type AlGaN structure with the gradually changed V type Al component is subjected to polarization doping. The Al component in the P type AlGaN structure with the gradually changed V type Al component is different from the Al component in the multi-quantum well structure. The P type AlGaN structure with the gradually changed V type Al component is far away from a P type GaN layer on the surface of the substrate. Based on the P type AlGaN structure with the gradually changed V type Al component, obtained electron holes are higher in concentration. Therefore, the internal quantum efficiency and the emission power of the UV LED are improved.

The invention discloses a method and device for detecting ultraviolet (UV) sterilization effect. The method comprises the following steps: (1) determining the relationship among the UV radiation strength, UV radiation time, and sterilization rate; (2) detecting the UV radiation strength; (3) obtaining the sterilization rate according to the UV radiation strength and a given radiation time. The device comprises a UV strength detection device, a time setting device, and a sterilization rate calculation module. The method and device can guarantee the effectiveness of a UV sterilization facility on killing bacteria (especially staphylococcus aureus), the sterilization process, which cannot be observed by naked eyes, can be evaluated and controlled, moreover, the UV sterilization facility can be stopped after the staphylococcus aureus is completely killed, the energy waste is avoided, and the practicality of the UV sterilization facility is improved.

The invention discloses a semiconductor laser with enhanced luminous efficiency. According to the laser, on the basis of a traditional semiconductor laser preparation technology, high-vacuum equipment is adopted to performing cleavage on a laser epitaxial wafer in an ultrahigh-vacuum environment and cavity surface metal nanometer particle and cavity surface film preparation are performed. According to the laser disclosed by the invention, uniformly distributed metal nanometer particles are prepared on laser resonance cavity surface, free electrons of metal nanometer particles are utilized to be coupled with incident electromagnetic waves, collective oscillation of free electrons is caused, an enhanced local area electric field is generated, a strong near field enhancing effect is provided, radiative recombination of active region carriers of the laser is enhanced, and improvement of the luminous efficiency of the semiconductor laser device is realized.

The invention discloses a P-type doped AlScN/AlScN superlattice barrier layer-based efficient light-emitting diode and preparation method, and mainly solves the problems that an existing p-type regionis low in hole injection efficiency, and electronic leakage exists in a quantum well. The efficient light-emitting diode comprises a gallium oxide substrate layer, a high-temperature AlN nucleating layer and an n-type GaN layer from bottom to top, wherein an electrode and a working region layer are arranged on the n-type GaN layer; an electron blocking layer, a p-type layer and an electrode are sequentially arranged on the upper surface of the working region layer, and the working region layer comprises six periods AlxGa1-xN/AlyGa1-yN multi-quantum-well layer and a barrier layer; and the barrier layer adopts a P-type doped AlmSc1-mN/AlnSc1-nN superlattice structure, so that electron depletion with the electron blocking layer is realized. According to the light-emitting diode, electronic leakage is reduced, the hole injection potential barrier is reduced, the hole concentration in the quantum well is improved, and the light-emitting diode can be used for preparing efficient ultravioletand deep ultraviolet light-emitting equipment.

A flip-chip LED chip and a manufacturing method thereof are provided, A buff layer and a light emitting structure are sequentially formed on that substrate, wherein the light emitting structure includes a first semiconductor layer, an active layer, a second semiconductor layer, metal reflective electrode layer, metal barrier layer, first reflective passivation layer, a first electrode and a secondelectrode, forming a second reflective passivation layer on the surface of the light emitting structure, etching the second reflective passivation layer, forming a first bare region on the surface ofthe first electrode, forming a second bare region on the surface of the second electrode, forming a first pad on the first bare region, and forming a second pad on the second bare region. The light emitted from the active layer passes through the metal reflective electrode layer, the first reflective passivation layer and the second reflective passivation layer, part of which is refracted from the side wall of the flip chip and part of which is reflected back to the side of the substrate, thereby greatly improving the light emitting efficiency of the active layer without adding additional complex processes, thereby increasing the brightness of the chip.

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 relates to an organic material and perovskite material combination-based full-solution flexible white-light device. The device sequentially comprises a substrate, a positive electrode, ahole transmission layer, an organic light-emitting active layer I, a perovskite light-emitting layer II, an organic light-emitting active layer III and a negative electrode from bottom to top. By thedevice, the problems that the process in the prior art is complicated, the manufacturing cost is high and an exciton composite region is needed to be accurately controlled are solved.

The invention discloses an ultraviolet light-emitting diode with a p-i-n type multi-quantum well structure. The ultraviolet light-emitting diode is provided with a substrate, an AlN buffer layer, an n-type AlGaN layer, a p-i-n type multi-quantum well active region, an electron blocking layer, a p-type AlGaN layer, a p-type GaN ohmic contact layer, an n-type electrode which is arranged on the n-type AlGaN layer and a p-type electrode which is arranged on the p-type GaN ohmic contact layer distributed from bottom to top in sequence. According to the ultraviolet light-emitting diode with the p-i-n type multi-quantum well structure, the carrier concentration and injection efficiency can be improved; an electric field opposite to an original built-in electric field in direction can be formed by utilizing the concentration difference of carriers in adjacent regions with different doping concentrations, and the original built-in electric field between a p type region and an n type region can be weakened, and the quantum limited stark effect caused by the built-in polarized electric field is reduced,so that the radiation recombination efficiency of electrons and holes is improved, and the light emitting power of the ultraviolet light-emitting diode is enhanced.

The invention discloses a multi-quantum well-based light-emitting diode and a preparation method thereof, and the light-emitting diode comprises a substrate, and also comprises a buffer layer, a non-doped GaN layer, an N-type GaN layer, a multi-quantum well layer, an electron blocking layer and a P-type GaN layer which are sequentially stacked on the substrate. Wherein the multi-quantum well layer comprises a plurality of quantum well layers and quantum barrier layers which are periodically and alternately stacked, each quantum well layer sequentially comprises a first quantum well sub-layer, a second quantum well sub-layer and a third quantum well sub-layer, and the first quantum well sub-layer is arranged on the N-type GaN layer; the first quantum well sub-layer comprises a first GaN layer and a second GaN layer arranged on the first GaN layer, and the first GaN layer is arranged on the N-type GaN layer; the third quantum well sub-layer comprises a first InGaN layer and a second InGaN layer arranged on the first InGaN layer, the first InGaN layer is arranged on the second quantum well sub-layer, and the technical problem that in the prior art, due to the fact that an InGaN quantum well layer grows at a low temperature, the crystal quality of the multi-quantum well layer is reduced, and the light emitting efficiency of the multi-quantum-well-based light emitting diode is affected can be solved.

The invention provides an epitaxial wafer of a deep ultraviolet light emitting diode with a bipolar AlN template layer, and belongs to the technical field of photoelectron manufacturing. The epitaxial wafer comprises a substrate, and an AlN template layer, an n-type AlGaN layer, a multi-quantum well layer and a p-type layer which are sequentially formed on the substrate, wherein a plurality of first polarity areas and a plurality of second polarity areas are arranged on the surface, far away from the substrate, of the AlN template layer, the first polarity areas and the second polarity areas are alternately distributed in the same direction, the first polarity areas are in aluminum polarity, and the second polarity areas are in nitrogen polarity. According to the epitaxial wafer of the invention, the radiation recombination of carriers can be promoted, and the luminous efficiency of the deep ultraviolet light-emitting diode is greatly improved.

The invention provides a growth method of a light emitting diode epitaxial wafer, which belongs to the technical field of semiconductors. The growth method comprises the following steps of providing asubstrate, sequentially growing a low-temperature buffer layer, a high-temperature buffer layer, an N-type layer, an active layer, an electron blocking layer and a P-type layer on the substrate, after the P-type layer completely grows, conducting n times of annealing treatment on the P-type layer, n being larger than or equal to 2 and smaller than or equal to 8, growing a P-type GaN sub-layer onthe P-type layer every time the annealing treatment is carried out, and then conducting next annealing treatment on the P-type layer and the P-type GaN sub-layer until n-1 P-type GaN sub-layers grow on the P-type layer, and enabling the thickness of each P-type GaN sub-layer to be not more than 6nm. By the adoption of the growth method, the number of holes injected into the active layer can be increased, so that radiation recombination of electrons and holes in the active layer is improved, and finally the internal quantum efficiency of the light-emitting diode is greatly improved.