134 results about "Electron recombination" patented technology

An organic light-emitting device with enhanced operational stability comprising an anode; a hole-transporting layer disposed over the anode; a light-emitting layer disposed over the hole-transporting layer for producing light in response to hole-electron recombination, wherein the light-emitting layer includes at least one organic host material and one organic luminescent dopant material; a stability-enhancing layer disposed in contact with the light-emitting layer, wherein the stability-enhancing layer includes at least one organic host material and one inorganic dopant material; an electron-transporting layer disposed over the stability-enhancing layer; and a cathode disposed over the electron-transporting layer.

PbI₂ thin film crystallization control is prerequisite of high-quality perovskite layer for the sequentially solution-processed perovskite solar cells. According to the present invention, an efficient-and-simple method has been developed by adding halogen acid additive to improve perovskite thin-film quality and an efficiency of at least 15.2% is obtained. This approach improves coverage, uniformity and stability of pervoskite thin-film. In addition, a nanofiber scaffold is incorporated into the perovskite layer so as to reduce the amount of grain boundaries, thus substaintially reducing electron recombination within these boundaries.

The invention discloses a quantum dot light emitting diode and a preparation method thereof. The quantum dot light emitting diode comprises a substrate, an anode, a hole transport layer, a quantum dot light emitting layer, an electron transport layer and a cathode in sequence from bottom to top, wherein the materials of the quantum dot light emitting layer include quantum dots and an amorphous insulating compound. The quantum dot light emitting layer is prepared by forming a film through spin coating of solution of the amorphous insulating compound containing the quantum dots, in order to weaken the electric field intensity at the quantum dot light emitting layer. Therefore, the possibility of electron recombination is improved while the electron and hole injection barriers are reduced, and thus, the efficiency and service life of QLED devices are increased effectively.

A method for forming a color organic light-emitting device including depositing a first electrode over a substrate; depositing a first emissive layer over the first electrode for producing a first colored light in response to hole-electron recombination; and selectively patternwise depositing a hole-blocking layer over the first emissive layer. The method also includes depositing a second emissive layer over the hole-blocking layer which in response to hole-electron recombination emits colored light different from the colored light emitted from the first emissive layer; depositing a second electrode over the second emissive layer; and whereby the patternwise deposition of the hole-blocking layer has been selected to substantially shift hole-electron recombination from the second to the first emissive layers.

An organic electroluminescent device includes an anode; a hole-transporting layer disposed over the anode, a light-emitting layer disposed over the hole-transporting layer for producing light in response to hole-electron recombination, and an electron-transporting layer disposed over the light-emitting layer. The device also includes a crystallization-inhibitor incorporated within the electron-transporting layer, wherein the crystallization-inhibitor prevents the electron-transporting layer from crystallizing during operation, and a cathode disposed over the electron-transporting layer.

An organic light-emitting device with improved performance including an anode formed over a substrate; a hole-transporting layer formed over the anode; and a light emitting layer formed over the hole-transporting layer for producing light in response to hole-electron recombination. The organic light-emitting device also includes an emission-protecting layer formed over the light-emitting layer, wherein the emission-protecting layer includes one or more materials selected to resist the surface contamination on the organic light-emitting layer and to ensure that there will be less surface contamination than if such layer had not been provided; an electron-transporting layer formed over the emission-protecting layer; and a cathode formed over the electron-transporting layer.

The invention discloses a method for preparing anatase titanium dioxide sol used for solar batteries. The method comprises the following steps of: performing coprecipitation titration of a titanium source and reaction solution to obtain a white precipitate of titanium hydroxide, dissolving the precipitate in a molar ratio of Ti4<+> to organic acid to hydrogen peroxide of 1:2:2-1:10:10, adjusting a pH value to 7.5, and standing the mixed solution stand for 12 hours to obtain a precursor of titanium dioxide sol; and performing hydrothermal treatment of the precursor of titanium dioxide sol at the temperature of between 70 and 250 DEG C to obtain the yellow anatase titanium dioxide sol. The anatase titanium dioxide sol used for dye-sensitized solar batteries undergoes spin coating or spray coating to form a film which is the titanium dioxide dense film used for high-performance dye-sensitized solar batteries, the bonding degree between the titanium dioxide film and the matrix is improved, the contact between the electrolyte and an light anode can be effectively avoided, so that the electron recombination is lowered, the performance of the battery is greatly improved, and the industrialization of the dye-sensitized solar battery industry is pushed forward.

The invention relates to a perovskite solar cell provided with a composite electron transport layer structure. The perovskite solar cell comprises a composite electron transport layer. The perovskite solar cell is characterized in that the composite electron transport layer is made of SnO2. According to the perovskite solar cell of the invention, a SnO2 and TiO2 composite material formed by treating the SnO2 with a TiCl4 aqueous solution is adopted, so that the conduction band energy level of the pure SnO2 is improved, the electron recombination of the solar cell adopting the SnO2 as the electron transport layer structure can be suppressed, and therefore, the efficiency of the cell can be remarkably improved; and the SnO2 and TiO2 composite electron transport material is prepared under low temperature which is below 180 DEG C, and therefore, energy consumption of cell protection can be decreased, and cost can be reduced.

The ZnO-base blue diode comprises: from bottom to top, a circular substrate, a buffer layer prepared on substrate to improve material epitaxial grow quality, a n-ZnO layer with edge etched as ring stage for ring Au/Ti electrode, an i-ZnO active layer for hole-electron recombination, a p-ZnO layer to provide being injected holes; an Au/Ni layer benefit to diffusion of injected current, an Au/Ni electrode contacted with wire, and a ring Au/Ti electrode on the said stage.

The invention relates to an LED epitaxial wafer which structurally comprises a sapphire substrate, a low-temperature gallium nitride-based buffer layer, an undoped gallium nitride layer, an n-type gallium nitride layer, multiple quantum wells, a p-type gallium nitride layer, a p-type aluminum gallium nitride layer, a coarsened p-type gallium nitride layer and an expanded current layer in sequence from the bottom up, wherein the expanded current layer can be embedded into the p-type gallium nitride layer or embedded into the p-type aluminum gallium nitride layer or embedded into the coarsened p-type gallium nitride layer. A manufacturing method of the LED epitaxial wafer comprises the step of embedding and growing the expanded current layer into the p-type gallium nitride layer, the p-type aluminum gallium nitride layer or the coarsened p-type gallium nitride layer. Because the forbidden bandwidth of the expanded current layer is smaller, the activation energy of Mg is reduced, the number of cavities entering a light-emitting area is increased, the injection ratio of the cavities in the light-emitting area is improved, and the number of the cavities compounded with electrons for emitting light is increased, thereby the illumination intensity of an LED is improved.

The invention discloses dithiophene pyrrole bridge-indoline organic dyes with the following structural formula which is shown in the specification, wherein R1 is C1-C6 alkoxy, a structural formula of Ar is (II) or (III); in the formula (II) and (III) which are shown in the specification, R2 is C1-C6 alkyls. A preparation method of the dithiophene pyrrole bridge-indoline organic dyes comprises the following steps of: using indoline boron ester, tetra triphenylphosphine, potassium carbonate and dithiophene pyrrole bromal substituted by alkoxy triphenylamine as materials; and obtaining a target through Suzuki coupling reaction and Knoevenagel condensation reaction in sequence, wherein the target can be used as a photosensitizer of a dye-sensitization solar cell. The preparation method disclosed by the invention has the advantage that a molar absorption coefficient and absorbing ability to light of dye molecules can be effectively improved by introducing the dithiophene pyrrole bridge into the indoline dyes; printed electrons can be effectively compounded and open-circuit voltage can be effectively improved by introducing large steric-hindrance groups into the indoline and the dithiophene pyrrole bridge, so that photoelectric conversion efficiency of the solar cell is improved.

The invention discloses isodiketopyrrolopyrrole dyes and application thereof. According to the invention, 4,4'-dihexyloxytriphenylamine is used as an electron donor, isodiketopyrrolopyrrole is used as a Pi bridge, cyanoacetic acid is used as an electron acceptor and an anchoring group, and an alkyl chain is introduced on an isodiketopyrrolopyrrole group, so a series of purely organic dyes based on isodiketopyrrolopyrrole are synthesized. The dyes have good light-harvesting performance and large steric hindrance and hardly aggregate when adsorbing on a semiconductor membrane. The purely organic dyes with isodiketopyrrolopyrrole as the Pi bridge of electrons are applied in dye-sensitized solar cells and have good capability in inhibiting electron recombination; and the dye-sensitized solar cells have high photoelectric conversion efficiency.

The invention belongs to the field of solar photovoltaic cells, and particularly relates to a CZTS nanometer array thin film solar photovoltaic cell and a manufacturing method thereof. According to the solar photovoltaic cell of a nanometer structure, the characteristics that the diameter of nanowire arrays is small, light rays are absorbed in the axial direction of the nanowire arrays and the distance between the nanowire arrays is smaller than the wavelength of light waves are utilized at the same time, and therefore light absorption is improved; by means of the preferred orientation of the nanowire arrays, the dot matrix distortion is reduced, and the light reflection is reduced; by means of the characteristic that the specific surface area of the nanowire arrays is large, the probability of carrier generation is increased; due to the fact that carriers are conveyed in the radial direction, the probability of electron holes and electron recombination is lowered, and the photoelectric conversion efficiency of the solar photovoltaic cell is greatly improved.

The invention provides a organic molecular dye with low energy level difference used in an organic dye-sensitized solar cell, a dye as shown in Formula 1. Due to the diazosulfide, the multi-level donor-acceptor structure in molecules and the electron withdrawing and releasing effect in the molecules, the dye has a broader absorption spectrum which can reach 800nm. The dye is one of the existing gmaterials with the broadest spectrum for absorption of sunlight in the dye-sensitized solar cell. Flexible chains in the molecules can not only improve the solubility of the molecules, thereby reducing difficulties in synthesis, purification and processing, but also can reduce the aggregation of the molecules in the device, thereby reducing the risk of hole-electron recombination. The structure and photophysical properties of the dye have large control space. The dye-sensitized solar cell with the composition with the low energy level difference as the sensitizing dye has high photoelectric conversion efficiency which can reach 9 percent to the maximum and is at the international advanced level. The Formula 1 is as follows.

The invention discloses a ZnO/graphene compound nano structure photo-anode for a dye-sensitized solar cell and a manufacture method of the ZnO/graphene compound nano structure photo-anode. The ZnO/graphene compound nano structure photo-anode is of a ZnO/graphene compound nano structure comprising ZnO nano particles with graphene with excellent electronic transmission property, and is manufactured on a conductive substrate by adopting a screen printing process. Because the graphene is introduced to be used as a collection and transmission channel of optical excitation electrons, compared with the existing ZnO nano particle photo-anode which is not added with graphene, the ZnO/graphene compound nano structure photo-anode disclosed by the invention has the advantages that the electron compound loss is effectively reduced, simultaneously the light absorption efficiency of the solar cell can be increased, and the short-circuit current of the solar cell is remarkably increased, therefore, the photovoltaic conversion efficiency of the solar cell is increased. Meanwhile, the ZnO/graphene compound nano structure photo-anode has the advantages of simpleness in operation of the manufacture method and procedures, low cost and capability of large-scale production.

The invention discloses a perovskite solar cell taking hydroxyl-containing organic amine as an interface modification layer. The perovskite solar cell comprises a transparent conductive layer, an electron transmission layer, a perovskite absorption layer, a hole transmission layer and a back electrode layer, wherein the interface modification layer is arranged between the perovskite absorption layer and the electron transmission layer or the hole transmission layer, the perovskite solar cell is characterized in that the interface modification layer is the hydroxyl-containing organic amine, thestructure formula of the hydroxyl-containing organic amine is R(OH)x(NH2)y, R is alkyl of C1-C12 or substituted or non-substituted aryl, x is more than or equal to 2, and y is more than or equal to 1. The hydroxyl-containing organic amine provided by the invention is used as the interface modification layer, the appetency of the electron transmission layer or the hole transmission layer is improved, better carrier transmission is achieved, electron recombination is reduced, and the photoelectric conversion efficiency of the prepared perovskite solar cell can reach 20.38%.

The invention discloses an epitaxial wafer of a light emitting diode and a preparation method thereof, belonging to the field of light emitting diode manufacturing. The barrier of the AlGaN barrier layer disposed in the first superlattice structure close to the N-type GaN layer side is higher than the barrier of the GaN barrier layer in the second superlattice structure between the first superlattice structure and the electron blocking layer. The AlGaN barrier layer may block most of the electrons in the InGaN well layer in the first superlattice structure. In this case, holes partly from theP-type GaN layer enter the active layer, It doesn't immediately recombine with electrons to emit light, under the condition that the hole migration rate is constant, the depth at which holes can enterthe active layer increases, in addition to emitting light recombination with electrons trapped in the InGaN well layer in the first superlattice structure, Some holes can also recombine with some electrons which have migrated into the second superlattice structure, and the number of holes which have the opportunity to recombine with electrons in the active layer is increased, which finally improves the luminescence efficiency of the light emitting diodes.

The invention discloses a photocatalyst for CO2 reduction and preparation method thereof. The photocatalyst disclosed by the invention is prepared by compounding g-C3N4 and transition metal carbide, calcining at a high temperature and partially oxidizing, and has a Z-shaped carrier transport characteristic, the formed Z-shaped heterojunction reduces the hole electron recombination rate, an oxidation reaction and a reduction reaction on the catalyst are separated, and the photocatalytic activity of the photocatalyst is improved. Therefore, the photocatalytic CO2 reduction efficiency and stability are improved. The specific surface area of the catalyst is large, the photo-thermal effect caused by high light absorption intensity of the catalyst enables the photocatalytic activity to be improved, products such as CO are easy to desorb on the surface of the catalyst, reuse of active sites is facilitated, and the stability of the photocatalyst is enhanced. The catalyst has a good applicationprospect in the field of photocatalytic CO2 reduction, the raw materials are cheap, the preparation method and operation are simple, and the catalyst is suitable for large-scale production.

The invention discloses a light emitting diode epitaxial wafer and a manufacturing method thereof, and belongs to the technical field of semiconductors. The epitaxial wafer comprises an insertion layer, a low-temperature P-type layer, an electron blocking layer, a high-temperature P-type layer and a P-type contact layer which are sequentially stacked on a multi-quantum well layer; the insertion layer is an AlN layer, the low-temperature P-type layer is a Mg-doped AlGaN/GaN superlattice structure or Mg-doped AlGaN/InGaN superlattice structure, the AlN layer is matched with the low-temperature P-type layer, the effect of a part of the electron blocking layer can be shared, and the thickness of the electron blocking layer can be reduced, so that the blocking effect on the hole is reduced, andmore holes can emit light by combining with electrons on the multi-quantum well layer, and the internal quantum light-emitting efficiency of the LED is improved. The total thickness of the insertionlayer, the low-temperature P-type layer, the electron blocking layer, the high-temperature P-type layer and the P-type contact layer is 40-100 nm, the thickness of the P-type layer is reduced, and theexternal quantum light-emitting efficiency of the LED is improved.

The invention provides benzothiadiazole-cyanocinnamic acid receptor-containing organic dye and its use in a dye-sensitized solar cell and belongs to the field of organic dye. The benzothiadiazole-cyanocinnamic acid receptor-containing organic dye utilizes triarylamine as an electron donor and utilizes benzothiadiazole-cyanocinnamic acid as a dye molecule receptor so that a molecular energy gap is reduced obviously, electron recombination in the cell is reduced and cell open-circuit voltage is effectively improved. The benzothiadiazole-cyanocinnamic acid receptor-containing organic dye has a simple synthesis route and can be purified easily. A dye-sensitized solar cell prepared from the benzothiadiazole-cyanocinnamic acid receptor-containing organic dye has open-circuit voltage of 839mV, a short-circuit photoelectric current of 17.95mA/m<2> and power conversion efficiency of 11%.