45results about How to "Suppression of non-radiative recombination" patented technology

The invention provides a method for growing a quantum well stress release layer of an epitaxial structure and the epitaxial structure. The epitaxial structure comprises the quantum well stress release layer with the total thickness of 160nm. The quantum well stress release layer is an HT MQW layer doped with In and Al and comprises a GaN layer with the thickness of 40nm and an AlyInxGa(1-x-y)N layer with the thickness of 2nm, wherein x ranges from 0.05 to 0.08, and y ranges from 0.02 to 0.05. According to the growing method, by modifying the energy band diagram of the HT MQW, electrons entering a luminous zone can be blocked, and the probability that the electrons enter a p layer and are recombined with holes in a nonradiative mode is reduced; moreover, the electrons blocked in the HT MQW are injected into the luminous zone more evenly through two-dimensional diffusion, the efficiency of the recombination between the electrons and the holes is promoted, and the luminance is improved.

The invention discloses a low-roll-off quasi-two-dimensional perovskite light-emitting diode and a preparation method thereof. The low-roll-off quasi-two-dimensional perovskite light-emitting diode issequentially provided with a cathode, a hole transport layer, a hole transport layer and light-emitting layer interface modification layer, a perovskite light-emitting layer, a light-emitting layer and electron transport interface modification layer, an electron transport layer, an electron injection layer and an anode from bottom to top. By modifying the interface of the hole transport layer andthe perovskite light-emitting layer, the hole injection barrier between the hole layer and the light-emitting layer is reduced, the hole injection efficiency is improved, the hole layer can be prevented from quenching the perovskite layer, and the light-emitting efficiency of the perovskite layer is improved. The interface of the perovskite light-emitting layer and the electron transport layer isalso modified, so that the defect state of the perovskite surface can be passivated, the film quality of the light-emitting layer is improved, non-radiative recombination is inhibited, and the light-emitting efficiency of the device is further improved.

The invention discloses a preparation method of a low-defect quasi-two-dimensional perovskite film based on methanesulfonic acid negative ion induction. According to the method, methanesulfonic acid (MeS) negative ions are led in an L2An-1MnX3n+1 perovskite precursor to adjust phase compositions, so that a more effective energy transfer way is generated. Crystal boundary and surface defect inactivation is achieved by the MeS negative ions, and non-radiative recombination is effectively restrained. The service life of an exciton of the prepared quasi-two-dimensional perovskite film is obviouslyprolonged, and three-dimensional perovskite crystal particles are obviously increased. CsMeS is added into quasi-two-dimensional metal halide perovskite precursor solution to adjust perovskite phasecompositions, so that more three-dimensional perovskite crystal particles are generated as compared with a traditional method, and the more effective energy transfer way is generated. According to themethod, mixing of perovskite crystal lattices in the used CsMeS is omitted, the crystal lattices only exist on the surfaces of the perovskite crystal lattices, crystal boundary and surface defect inactivation can be achieved by MeS negative ions in the CsMeS, and non-radiative recombination is effectively restrained.

The invention discloses a GaN-based LED (Light-Emitting Diode) device with a two-dimensional electron gas structure, and a preparation method for the GaN-based LED device. The LED device comprises a substrate, a GaN nucleating layer, a GaN buffer layer, a non-doped GaN layer, an N-type GaN layer, the two-dimensional electron gas structure, a multi-quantum well luminous layer and a P-type GaN layer. According to the LED device, the two-dimensional electron gas structure is an electron emission layer formed by alternately stacking a plurality of pairs of lightly-doped n-GaN layers / AlN layers / heavily-doped n+GaN layers from bottom to top, the overflow of electrons into a non-quantum well area for nonradiative recombination with electron holes under a heavy-current injection condition can be effectively inhibited, and in addition, by two-dimensional electron gas, the transverse spreading efficiency of the electrons can be improved to improve the luminous efficiency of LEDs under the heavy-current injection condition.

The invention discloses a perovskite solar cell based on an organic molecule passivator and a preparation method of the perovskite solar cell, and belongs to the field of solar cells. The structure comprises a transparent conductive substrate, an electron transport layer, a perovskite absorption layer, an organic molecule passivation layer, a hole transport layer and a metal electrode. The organic molecule passivator is at least one of compounds and derivatives thereof, wherein benzene rings of the compounds comprise -COOH or -CH3O, such as p-methoxyphenylacetic acid, anisole and phenylacetic acid. When the passivator is used for passivating the upper surface and the lower surface of the perovskite thin film or the interior of the thin film, the defect density on the surface of the perovskite thin film or in the perovskite thin film can be effectively reduced, non-radiative recombination is inhibited, the built-in electric field of the perovskite thin film is enhanced, and the performance of the perovskite solar cell is improved. The organic molecule passivator provided by the invention is suitable for single-junction perovskite solar cells, perovskite / crystalline silicon or perovskite / perovskite multi-junction laminated solar cells and the like, and has a wide application prospect.

The invention discloses a blue light perovskite with a high quantum yield and a preparation method and applications thereof, and relates to the technical field of luminescent materials. The blue light perovskite has a high quantum yield and a light emission adjustable property, and the full blue light spectrum is covered. According to the preparation method, through PrCl3 doping, the surface of perovskite is optimized, the vacancy defects in the perovskite surface are passivated, the surface ligands are reduced, non-radiation recombination is reduced, intrinsic radiation recombination is increased, and the quantum yield is improved.

The invention provides an efficient and stable inorganic lead-free perovskite solar cell and a preparation method thereof. The solar cell comprises a conductive substrate, a PEDOT: PSS layer, an inorganic lead-free CsSnI3 perovskite layer, a C60 layer, a BCP layer and a metal counter electrode layer which are sequentially arranged from bottom to top; and the inorganic lead-free CsSnI3 perovskite layer is a CsSnI3 perovskite layer passivated by thiourea small molecular organic matters. According to the invention, a thiourea small molecular organic matter is used as a surface passivator of CsSnI3 perovskite, and a trans-structure (a conductive substrate / PEDOT: PSS layer / inorganic lead-free CsSnI3 perovskite layer / C60 layer / BCP layer / metal counter electrode layer) perovskite solar cell is constructed; the photoelectric conversion efficiency of the obtained solar cell is greatly improved, and the solar cell has good long-term working stability.

The invention relates to application of an organic phosphonium salt molecule in a perovskite solar cell and a preparation method of a device of the organic phosphonium salt molecule, and belongs to the technical field of perovskite solar cells. Zwitterions in the organic phosphonium salt molecules and a perovskite thin film have chemical effects, interface defects of the perovskite thin film are effectively passivated, the service life of carriers of the perovskite thin film is prolonged, non-radiative recombination of interface carriers is inhibited, and therefore the power conversion efficiency and stability of the device are improved at the same time, and controllable preparation of the efficient and stable perovskite solar cell is realized.

The invention provides a forward-direction triple junction solar cell based on a p-type doped quantum well structure, and the solar cell comprises a quantum well layer and a spacing layer, wherein the quantum well layer and / or the spacing layer are / is of a p-type doped type. According to the invention, the quantum well layer and / or the surrounding spacing layer are / is intentionally of the p-type doped type, thereby inhibiting the nonradiative recombination of the quantum well structure, facilitating the effective separation of photon-generated carriers, achieving the purposes of reducing a low dark current and improving a short circuit current, and finally obtaining a big short circuit current triple junction solar cell. The p-type doped quantum well structure can improve the response of carriers to a band with the wavelength being greater than 880nm, and improves the short circuit current density of the cell.

The embodiment of the invention discloses a distributed feedback laser chip and a preparation method thereof. The laser chip comprises a substrate, a laser structure located on one side of the substrate, a first electrode and a second electrode. A grating pattern is arranged on the side, adjacent to the second electrode, of the laser structure, the grating pattern comprises a ridge-shaped structure, the ridge-shaped structure comprises first areas and second areas which are circularly arranged in the first direction, and the refractive index of the first areas is larger than that of the secondareas; the second electrode covers the ridge-shaped structure, extends to partial regions of the second regions and is in contact with a film layer, close to one side of the substrate, of the film layer where the grating pattern is located, wherein the first direction is parallel to the plane where the substrate is located. The technical scheme of the embodiment of the invention has the advantages of high modulation rate, high internal quantum efficiency, low resistance, good single-mode characteristic, small stress, low cost and the like, can greatly improve the modulation rate, the electro-optical conversion efficiency, the single-mode characteristic, the production yield and the like of the laser, and is very beneficial to large-scale production and application.

The invention discloses a tin-based perovskite solar cell with optimized components and a preparation method thereof. The tin-based perovskite solar cell structurally comprises an indium tin oxide (ITO) conductive glass layer, an electron transport layer, a perovskite light absorption layer, a hole transport layer and a silver electrode layer in sequence, the material of the electron transport layer is PC61BM. Phenylethylamine halide salt is introduced into the perovskite precursor solution, thin film crystallization is improved, non-radiative recombination is inhibited, and the charge extraction capacity is improved. The phenylethylamine halide salt and the phenylethylamine halide salt derivative remarkably improve the photoelectric property of the tin-based perovskite solar cell, so that the photoelectric conversion efficiency of the tin-based perovskite cell can reach 10.51%, the stability of the prepared tin-based perovskite cell is remarkably improved, and further development of the tin-based perovskite cell is promoted.

The invention belongs to the technical field of crystal material application, and discloses a two-dimensional organic-inorganic hybrid perovskite scintillator capable of simultaneously detecting gamma rays and fast neutrons and preparation of the two-dimensional organic-inorganic hybrid perovskite scintillator, the chemical formula of the organic-inorganic hybrid perovskite scintillator material is A2PbBr4 or A2PbBr4-xClx, wherein A is a protonated phenylethylamine (PEA) ion, a protonated benzimidazole (BI) ion or a protonated butylamine (BA) ion, x is 0-0.8, and the probe can be applied to detection of fast neutrons or simultaneous detection of gamma rays and fast neutrons. The two-dimensional organic-inorganic hybrid perovskite scintillator material composed of specific elements contains a large number of hydrogen atoms and heavy atoms at the same time, so that under excitation of gamma rays or fast neutrons, the material has high light yield and fast attenuation, and the scintillator is excellent in performance and especially can be used for detecting gamma rays and fast neutrons at the same time.

The invention provides a method for growing a quantum well stress release layer of an epitaxial structure and the epitaxial structure. The epitaxial structure comprises the quantum well stress release layer with the total thickness of 160nm. The quantum well stress release layer is an HT MQW layer doped with In and Al and comprises a GaN layer with the thickness of 40nm and an AlyInxGa(1-x-y)N layer with the thickness of 2nm, wherein x ranges from 0.05 to 0.08, and y ranges from 0.02 to 0.05. According to the growing method, by modifying the energy band diagram of the HT MQW, electrons entering a luminous zone can be blocked, and the probability that the electrons enter a p layer and are recombined with holes in a nonradiative mode is reduced; moreover, the electrons blocked in the HT MQW are injected into the luminous zone more evenly through two-dimensional diffusion, the efficiency of the recombination between the electrons and the holes is promoted, and the luminance is improved.

The invention discloses a gallium nitride light emitting diode and a preparation method thereof. The gallium nitride light emitting diode comprises pins, dustproof sleeves, sealing rings, a fixed base, bottom plates, fastening springs, a baffle, fixed clamping blocks, a packaging body, a protection sleeve, a first ceramic layer, a first anti-static layer, a heat dissipation layer, a waterproof layer, a second anti-static layer, a second ceramic layer, a diode body, a P type electrode, a GaN: Mg layer, an InGaN multi-quantum well, a GaN: Si layer, a GaN buffer layer, a sapphire substrate, an Ntype electrode, limiting springs, a mounting base, limiting blocks, a mounting partition plate and heat conducting adhesive; the pins are mounted on the two sides of the packaging body through the fixed base, and the outer sides of the pins are packaged with the dustproof sleeves; the baffle is mounted in the fixed base through a bolt; two bottom plates are mounted on the two sides of the top of the baffle through bolts; and the fastening springs are mounted on one sides of the bottom plates through buckles. The light emitting diode is convenient and quick to mount, stable in structure, has certain impact resistance and effectively improves use convenience.

The invention discloses a GaN-based LED structure, which sequentially comprises a substrate, a first N-type doped GaN layer, a first ZnGeN2 barrier layer, a second N-type doped GaN layer, a multi-quantum well layer and a P-type doped GaN layer from bottom to top. The invention also discloses a preparation method of the GaN-based LED structure.

The invention discloses a trans-solar cell preparation method based on seed crystal induced growth of a perovskite thin film. The chemical general formula of the seed crystal solution is CsPbBr3 / DMSO, the seed crystal solution contains self-dispersed CsPbBr3 small crystal lattices or seed crystals, and the seed crystal solution can be added into a perovskite precursor solution to prepare a perovskite thin film through seed crystal induced growth. According to the invention, a bottom-to-top crystal growth process of perovskite can be realized, and large-size through crystals are realized; the condition that an alpha photovoltaic phase of formamidino perovskite is easily converted into a delta phase in a room temperature environment is effectively inhibited, and a long-term stable perovskite thin film can be obtained. The invention also discloses a preparation method for preparing a trans (p-i-n) structured perovskite solar cell by using the seed crystal solution, the preparation method is compatible with a low-temperature annealing process in other functional layers, and the trans perovskite solar cell can be prepared at low temperature (less than or equal to 100 DEG C) in the whole process.

The invention provides a perovskite light-emitting diode and a preparation method thereof, and belongs to the technical field of light-emitting diodes. The perovskite light-emitting diode sequentially comprises a glass substrate with an ITO conductive thin film, a hole transport layer, a nano particle and / or cryptand doped quasi-two-dimensional perovskite light-emitting layer, an electron transport layer, a modification layer, and an electrodefrom bottom to top. The invention also provides a preparation method of the perovskite light-emitting diode. According to the invention, the light-emitting layer of the perovskite light-emitting diode is the nano-particle and / or cryptand doped quasi-two-dimensional perovskite film, the structural order distribution in the quasi-two-dimensional perovskite film can be narrowed through doping, the occurrence of lower or higher order phases is reduced, and thus non-radiative recombination in the film is inhibited; and based on the mechanism, a light emitting diode device with higher external quantum efficiency (EQE) is finally obtained.

The invention discloses a nano-porous structure deep ultraviolet LED device with an n-AlGaN layer and a manufacturing method of the nano-porous structure deep ultraviolet LED device. The nano-porous structure deep ultraviolet LED device comprises a sapphire substrate, an AlN layer, an n-AlGaN layer, a multi-quantum well layer, a p-AlGaN layer, a p-GaN layer, a p electrode and an n electrode, wherein the n-AlGaN layer and the AlN layer are sequentially arranged on the sapphire substrate from top to bottom, the n electrode and the multi-quantum well layer are arranged on the n-AlGaN layer, the p electrode 10, the p-GaN layer, the p-AlGaN layer and the multi-quantum well layer are sequentially arranged on the n-AlGaN layer from top to bottom, and a nano-porous structure is arranged in the n-AlGaN layer, and is located under the n electrode and the multi-quantum well layer. According to the invention, the LED device and the manufacturing method thereof can effectively achieve enhancement of light extraction efficiency.

The invention relates to an all-inorganic perovskite red light emitting diode based on cuprous iodide addition. The invention discloses an application of cuprous iodide in preparation of an all-inorganic perovskite film. The method for preparing the all-inorganic perovskite film comprises the following steps that an inorganic perovskite precursor solution is prepared, cuprous iodide is doped in the inorganic perovskite precursor solution, the surface of a substrate is coated with the inorganic perovskite precursor solution, and the all-inorganic perovskite film is formed on the surface of thesubstrate after annealing. The invention also provides an all-inorganic perovskite light emitting diode based on the all-inorganic perovskite film. Through doping of cuprous iodide, crystallinity, grain size improvement and device performance of the all-inorganic perovskite are effectively improved, and through a series of gradient doping, the device performance and stability are remarkably changed.

The invention discloses a semiconductor light-emitting unit and a cascaded mid-infrared light-emitting diode. The semiconductor light-emitting unit includes a hole barrier layer, an active layer and an electron barrier layer stacked in sequence, and a hole barrier layer and an electron barrier layer. The effective bandwidth of the barrier layer is larger than the effective bandwidth of the active layer, the conduction bands of the hole barrier layer and the active layer are equal to each other and the valence bands form a potential difference, and the valence bands of the electron barrier layer and the active layer are equal to each other. and the conduction band forms a potential difference. The cascaded mid-infrared light emitting diode includes the above-mentioned semiconductor light emitting unit. The invention solves the problem that the active region of the existing semiconductor light-emitting unit lacks heterojunction confinement, which affects its quantum efficiency and output power.

The invention discloses a preparation method of a blue light perovskite light-emitting diode. The preparation method comprises the following steps: preparing a passivating agent TMBBr, preparing a TMB2PbBr4 solution, synthesizing CsPbBr3 powder, preparing a quasi-two-dimensional blue light perovskite PEAxPA2-x (CsPbBr3) n-1PbBr4: TMBBr precursor solution, and preparing a three-dimensional mixed halogen perovskite light-emitting diode device. According to the invention, bis (trifluoromethylsulfonyl) imide sodium is used as an interface modification layer of nickel oxide (NiOx), and 4-(trifluoromethyl) benzamide hydrobromide is introduced into a quasi-two-dimensional perovskite precursor solution, so that the device has excellent spectral stability and better device performance.

The invention provides a manufacturing method of an LED epitaxial wafer, and the method comprises the following steps: step 3, manufacturing a plurality of protruding cones on an AlN layer at intervals; 4,manufacturing a plurality of concave and inverted conical cavities on the AlN layer at intervals, wherein the conical cavities and the cones are arranged in a staggered mode and are not connected in pairs; 5, periodically growing a plurality of multi-quantum well light-emitting layers on the AlN layer, wherein each multi-quantum well light-emitting layer comprises an InGaN well layer and a GaN barrier layer which are grown in sequence, the multi-quantum well light-emitting layer grown in the first period is used for filling the conical cavities in the step 4, and starting from the second period, the multi-quantum well light-emitting layer grown in the next period is located on an integral structure comprising the AlN layer and the multi-quantum well light-emitting layer grown in the previous period. According to the invention, the brightness of the LED epitaxial wafer can be improved, the antistatic capability is enhanced, the concentration ratio of wavelength is improved, and the forward voltage of the LED epitaxial wafer can be reduced.

The invention discloses a copper gallium sulfur / zinc selenide core-shell structure quantum dot and a preparation method and application thereof, and the preparation method comprises the following steps: firstly synthesizing a CuGaS2 core quantum dot, and then synthesizing a ZnSe shell layer on the surface of the CuGaS2 core quantum dot. The ZnSe shell layer in the core-shell structure quantum dot effectively passivates a large number of surface defects of a CuGaS2 core, improves the stability and effectively inhibits non-radiative recombination, and compared with pure copper-gallium-sulfur quantum dots, the zinc selenide shell layer coating effectively improves the saturation photocurrent of a quantum dot photoelectrochemical cell. The core-shell structure quantum dot can be applied to hydrogen production of a photoelectrochemical cell, and more electrons can be injected into a photoanode, so that the photocurrent density is improved.

The invention relates to the field of compound semiconductor optoelectronic devices, in particular to a device structure of a high-performance AlGaN-based deep ultraviolet light-emitting diode (LED) device and a preparation method of the device structure. The AlGaN-based deep ultraviolet light emitting diode device structure provided by the invention is provided with a V-shaped three-dimensional p-n junction injection structure. And the V-shaped three-dimensional p-n junction injection structure is formed by further forming an AlGaN electron barrier layer (EBL), a p-AlGaN and a p-GaN contact layer on the semi-polar surface of the side wall of the V-shaped corrosion pit of the AlGaN-based quantum well part. According to the V-shaped three-dimensional p-n junction injection structure, the inherent limitation that holes in an AlGaN-based deep ultraviolet LED which is widely used at present and grows on a (0001) plane sapphire substrate can only be injected in the [000-1] direction is changed, so that the problem of low injection efficiency caused by insufficient hole migration capability is effectively solved, and the hole concentration and uniform distribution in an LED device quantum well are remarkably improved; therefore, the light output power of the device is improved, and meanwhile, the Droop effect problem under large current injection is effectively solved.

The invention discloses a pyridine-based BODIPY-like passivation material, a preparation method thereof and an application of the material in a perovskite solar cell, and belongs to the field of photoelectric functional materials and devices. According to the invention, 2, 2-dipyridyl is used as a raw material to synthesize a BODIPY-like structure, and the BODIPY-like structure is loaded on the surface of perovskite to serve as a passivation layer of the perovskite solar cell. The synthesis route of the passivation material is simple, the conditions are mild, the solvent does not participate in the reaction, the yield is high, inert gas protection is not needed, and molecules with F as anions can be obtained; the unique structure can passivate inherent defects on the surface of the perovskite, inhibit non-radiative recombination, promote interface charge transmission, improve the light utilization rate and protect the perovskite from being eroded by water and solvents, so that the efficiency (photoelectric conversion efficiency reaches up to 20.7821%) and stability of the perovskite solar cell are improved.

The invention discloses a perovskite light-emitting diode with mixed cations and mixed anions and a preparation method thereof. The perovskite light-emitting diode sequentially comprises an electrode 1, a transport layer 1, a perovskite light-emitting layer, a transport layer 2 and an electrode 2 ; The perovskite light-emitting layer is a metal halide perovskite light-emitting material with mixed cations and mixed anions, which is composed of LX, AX and BX 2 Prepared, wherein L is an organic amine ion, A is a monovalent cation, B is a divalent metal cation, and X is I ‑ 、Br ‑ , Cl ‑ 、SCN ‑ 、TFA ‑ or CH 3 COO ‑ Two or more of them, and at least one halide ion. The present invention reduces the formation of perovskite cation vacancies and anion vacancies through the component regulation strategy of mixed cations and mixed anions, reduces the density of perovskite defect states, and suppresses the non-radiative recombination caused by vacancy defects, thereby improving PeLEDs Luminous efficiency.

The invention discloses a metal halide perovskite-polycarbonate composite fluorescent film and a preparation method and application thereof, and the method comprises the following steps: in the N2 atmosphere, spin-coating a perovskite precursor solution on a polycarbonate film, then spin-coating an anti-solvent, and annealing the obtained material to obtain a composite fluorescent film. Cations in the perovskite precursor solution are composed of Cs < + >, Pb < 2 + >, organic amine ions and Na < + >, or are composed of the organic amine ions, Cs < + > and Pb < 2 + >; and the perovskite precursor solution, the polycarbonate film and the anti-solvent are preheated at 30-80 DEG C before use. Through component regulation and control of the perovskite precursor solution, the composite compatibility of perovskite and PC is improved, the surface defect state density of perovskite crystals in the composite film is reduced, and the perovskite-PC composite film achieves high luminous efficiency while obtaining high stability.