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

Nitride light-emitting diode (LED) epitaxial wafer and growing method thereof

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.
Owner:YANGZHOU ZHONGKE SEMICON LIGHTING

Laser stripping film LED (Light-Emitting Diode) and preparation method thereof

The invention discloses a laser stripping film LED (Light-Emitting Diode) and a preparation method thereof. A chip unit of the laser stripping film LED comprises a type n layer, a quantum well, a type p layer, a periodical metal nanometer structure, an electrode p, an insulating layer and an electrode n, wherein the type p layer is formed on the quantum well; the periodical metal nanometer structure is embedded into the type p layer; the abovementioned structures inversely cover on a substrate; and a bonding pad p is arranged at one corner of a chip. According to the laser stripping film LED, the coupling resonance functions of surface plasmons and a quantum well structure are utilized, so that the radiation compounding efficiency and light-emitting efficiency of the LED are increased greatly under bulk injection, and meanwhile, certain effects are achieved on green-yellow light and ultraviolet light LEDs with low light-emitting efficiency; laser scribing and corroding methods are adopted for partitioning the chip unit, so that the warping of an epitaxial wafer is reduced, and the processing difficulty and cost are lowered; and specific to the bonding pad p, a protection layer and silver layer evaporation process is adopted, so that the manufacturing process of the bonding pad p is simplified, and the process cost is lowered; and a hot phosphoric acid coarsening method is adopted, so that the process cost is lowered, and the light-emitting efficiency of the LED is increased.
Owner:PEKING UNIV

Electroluminescent device

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.
Owner:CAMBRIDGE ENTERPRISE LTD

A method for corroding sapphire graphic substrate by wet-process

This invention relates to humid erosion sapphire pattern underlay method, which comprises the following steps: adopting general C surface sapphire silicon dioxide mask layer coated; using technique of etching technique to the silicon dioxide mask pattern along [1100] or [1120] direction; using sulfur acid or mixture liquid of sulfur and phosphorus acids as erosion liquid underlay; finally using the rare hydrofluoric acid liquid to erode the mask layer to get the sapphire round underlay.
Owner:INST OF PHYSICS - CHINESE ACAD OF SCI

Green nitride light-emitting diode (LED) epitaxial wafer and growth method thereof

The invention relates to a green nitride LED epitaxial wafer and a growth method thereof, and belongs to the technical field of semiconductor photo-electricity. The method is characterized in that an InGaN material layer with a low content of In components is grown between a quantum barrier and a quantum well in each quantum well active area when a plurality of quantum well active areas are grown; a quantum barrier is grown on a cap layer in a last quantum well active area, a hole injection layer is grown on the quantum well, and a p-AlGaN electronic blocking layer is grown on the hole injection layer. According to the green nitride LED epitaxial wafer and the growth method thereof, the process is reasonable, and the production is facilitated; LED chips are manufactured through a standard chip process, so that the internal quantum efficiency is improved, and the hole injection efficiency is improved greatly; and manufactured chips are high in luminous flux after being packaged, the inverse antistatic capacity reaches more than ten thousand volts, the electricity is not leaked under 8-volt inverse voltage measurement, and the working voltage is smaller than 3.1 volts under a 15 mA forward current.
Owner:YANGZHOU ZHONGKE SEMICON LIGHTING

Deep UV LED

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.
Owner:GUANGDONG UNIV OF TECH

Method and device for detecting ultraviolet (UV) sterilization effect

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.
Owner:罗旭

A method for corroding sapphire graphic substrate by wet-process

This invention relates to humid erosion sapphire pattern underlay method, which comprises the following steps: adopting general C surface sapphire silicon dioxide mask layer coated; using technique of etching technique to the silicon dioxide mask pattern along [1100] or [1120] direction; using sulfur acid or mixture liquid of sulfur and phosphorus acids as erosion liquid underlay; finally using the rare hydrofluoric acid liquid to erode the mask layer to get the sapphire round underlay.
Owner:INST OF PHYSICS - CHINESE ACAD OF SCI

Semiconductor laser with enhanced luminous efficiency

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.
Owner:CHANGCHUN UNIV OF SCI & TECH

P-type doped AlScN/AlScN superlattice barrier layer-based efficient light-emitting diode and preparation method

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.
Owner:XIDIAN UNIV

A flip-chip LED chip and a manufacturing method thereof

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.
Owner:FOSHAN NATIONSTAR SEMICON

High-speed LED optical communication modulator

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.
Owner:NANJING UNIV

High-speed LED optical-communication resonant-type modulator

The invention discloses a high-speed LED optical-communication resonant-type modulator. The modulator comprises a power supply unit, a control unit, an inductor, a resistor, a capacitor, an LED, a switch K101 and a switch K103; when the K101 and the K103 are connected, the voltage-limiting constant-current control unit provides a forward power supply for the LED, the LED is quickly overshot and connected then, and the resonant capacitor performs energy storage through the resonant inductor; and, when the K103 is still connected, the K101 is disconnected, resonance is generated between the inductor and the capacitor, a reverse power supply is provided for the LED in an LED reverse recovery time, and then the LED is quickly and electrically disconnected. The modulator further comprises a K102; and, when the K102 is connected, and when the K101 and the K103 are disconnected, forward one-way discharging of the LED is performed further. The composite rate of carriers is improved, so the switch speed is greatly improved; disconnection is further accelerated through an auxiliary discharge pathway; and energy zone bending is reduced through time sequence control, and radiation recombination of the carriers is improved.
Owner:NJU OPTOELECTRONICS ENG RES INST CO LTD

Organic material and perovskite material combination-based full-solution flexible white-light device and fabrication method thereof

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.
Owner:UNIV OF ELECTRONICS SCI & TECH OF CHINA

An ultraviolet led epitaxial structure

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.
Owner:SOUTH CHINA NORMAL UNIVERSITY

A kind of laser stripping film LED and preparation method thereof

The invention discloses a laser stripping film LED (Light-Emitting Diode) and a preparation method thereof. A chip unit of the laser stripping film LED comprises a type n layer, a quantum well, a type p layer, a periodical metal nanometer structure, an electrode p, an insulating layer and an electrode n, wherein the type p layer is formed on the quantum well; the periodical metal nanometer structure is embedded into the type p layer; the abovementioned structures inversely cover on a substrate; and a bonding pad p is arranged at one corner of a chip. According to the laser stripping film LED, the coupling resonance functions of surface plasmons and a quantum well structure are utilized, so that the radiation compounding efficiency and light-emitting efficiency of the LED are increased greatly under bulk injection, and meanwhile, certain effects are achieved on green-yellow light and ultraviolet light LEDs with low light-emitting efficiency; laser scribing and corroding methods are adopted for partitioning the chip unit, so that the warping of an epitaxial wafer is reduced, and the processing difficulty and cost are lowered; and specific to the bonding pad p, a protection layer and silver layer evaporation process is adopted, so that the manufacturing process of the bonding pad p is simplified, and the process cost is lowered; and a hot phosphoric acid coarsening method is adopted, so that the process cost is lowered, and the light-emitting efficiency of the LED is increased.
Owner:PEKING UNIV

Ultraviolet light-emitting diode with p-i-n type multi-quantum well structure

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.
Owner:SOUTHEAST UNIV

Algan-based deep ultraviolet LED epitaxial structure and preparation method of mg-doped quantum well

The invention discloses an AlGaN-based deep-ultraviolet LED epitaxial structure and a preparation method thereof, which utilize Mg-doped quantum wells to enhance luminous efficiency. The deep ultraviolet LED structure includes a substrate, a buffer layer, an AlN layer, a superlattice stress regulation / dislocation filter layer, a non-doped AlGaN layer, an n-type AlGaN layer, a Mg-doped active light-emitting region multi-quantum well layer, A p-type AlGaN layer and a p-type GaN contact layer. In the invention, Mg impurity is doped in the middle third of the well layer of the multi-quantum well active luminescent layer of the LED, so as to improve the internal quantum efficiency and light extraction efficiency of the LED. Compared with the non-doped multiple quantum well structure, the Mg-doped multiple quantum well structure can suppress the quantum confinement Stark effect, improve the spatial overlap of electron and hole wave functions and radiative recombination efficiency, and provide more holes Participate in radiative recombination and improve internal quantum efficiency. Moreover, Mg doping can also introduce a local strain field, increase the compressive strain in the quantum well, increase the ratio of TE polarized light, and finally improve the light extraction efficiency of AlGaN-based deep ultraviolet LEDs.
Owner:XIAMEN UNIV

Multi-quantum well-based light emitting diode and preparation method thereof

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.
Owner:JIANGXI ZHAO CHI SEMICON CO LTD

A kind of ultraviolet light-emitting diode with p-i-n type multi-quantum well structure

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.
Owner:SOUTHEAST UNIV

High-speed led optical communication resonant quasi-switching modulator

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.
Owner:NJU OPTOELECTRONICS ENG RES INST CO LTD

Epitaxial wafer of deep ultraviolet light emitting diode with bipolar AlN template layer

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.
Owner:HC SEMITEK ZHEJIANG CO LTD

High speed led optical communication modulator

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.
Owner:NANJING UNIV

A semiconductor laser with enhanced luminous efficiency

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.
Owner:CHANGCHUN UNIV OF SCI & TECH

Growth method of light emitting diode epitaxial wafer

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.
Owner:HC SEMITEK ZHEJIANG CO LTD

High-speed LED optical communication bridge-type modulator

The invention discloses a high-speed LED optical communication bridge-type modulator, and the modulator comprises a power supply unit, an LED, a switch K101, a switch K102, a switch K103, a switch K104, a switch K105, a control unit, a voltage-limiting constant current control unit, and a constant voltage control unit. The switches K101 and K102 are connected, and the switches K103, K104 and K105 are disconnected. The forwarding power supply of the LED is carried out, thereby enabling the LED to be quickly overshot and connected. The switches K103 and K104 are connected, and the switches K101, K102 and K105 are disconnected. The reverse power supply of the LED is carried out, thereby enabling the LED to be quickly turned off. The control of time sequence controls the time of reverse power supply through the monitoring of a reverse current of the LED, and the reverse power supply is not carried out in the whole disconnection process but in a small time period, so as to prevent band bending from causing the great decrease of radiative recombination rate, and improving the disconnection speed of light. The switch K105 is connected, and the switches K101, K102, K103 and K104 are disconnected. The switch K105 is a discharge circuit which aims at speeding up the recombination of residual carriers of the LED, and controls the forwarding unidirectional discharge of the LED. The modulator improves the recombination speed of carriers, and is high in switching speed.
Owner:NJU OPTOELECTRONICS ENG RES INST CO LTD

Preparation method of quasi-two-dimensional film

The invention discloses a preparation method of a quasi-two-dimensional thin film, belongs to the technical field of light emitting diodes and display, solves the problems of complex process and low efficiency of the existing quasi-two-dimensional thin film preparation, and has the technical key points that a perovskite thin film is composed of three-dimensional perovskite nanocrystals and a quasi-two-dimensional perovskite thin film, wherein the surface of the three-dimensional perovskite nanocrystal is modified by an appropriate long-chain organic ligand to adapt to a cascade energy transfer process in the film, and the three-dimensional perovskite nanocrystal with a specific group is introduced into an anti-solvent, so that the nanocrystal can be used as a crystallization seed in a film preparation process to regulate and control a crystal growth kinetic process of the film, and the film is prepared. The three-dimensional perovskite nanocrystal thin film has the advantages that internal defects are passivated, the non-radiative recombination probability in the thin film is reduced, an extra carrier transmission channel from a small n phase to the three-dimensional perovskite nanocrystal can be constructed, photon-generated carrier radiative recombination is promoted, the light emission efficiency of the thin film is effectively improved, and the thin film is simple in preparation process and high in efficiency.
Owner:JILIN UNIV
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