65 results about "Lead selenide" patented technology

A device comprising a doped semiconductor nano-component and a method of forming the device are disclosed. The nano-component is one of a nanotube, nanowire or a nanocrystal film, which may be doped by exposure to an organic amine-containing dopant. Illustrative examples are given for field effect transistors with channels comprising a lead selenide nanowire or nanocrystal film and methods of forming these devices.

The present application discloses a method and system of depositing a lead selenide film onto another material. The lead selenide film may used in a photoconductive application or a photovoltaic application. Furthermore, the applications may be responsive to infrared radiation at ambient temperature. In one embodiment, a method includes sputtering the lead selenide film, performing a sensitization process, and applying a passivation film. In one exemplary embodiment, a p-n junction is formed by directly adhering a lead selenide film to a silicon substrate.

A device comprising a doped semiconductor nano-component and a method of forming the device are disclosed. The nano-component is one of a nanotube, nanowire or a nanocrystal film, which may be doped by exposure to an organic amine-containing dopant. Illustrative examples are given for field effect transistors with channels comprising a lead selenide nanowire or nanocrystal film and methods of forming these devices.

A photoconductive bolometer infrared detector using a detector material that has a resistance changed due to photo-excitation and thermal-excitation from an incident radiation in the infrared range. The resistance changes caused by photo-excitation and the thermal excitation are additive for this detector material. The detector material is suspended over a substrate by a gap of one quarter wavelength of the incident radiation, such that the thermal absorption of the incident radiation can be enhanced. Preferably, the detector material is lead selenide that has a thermal coefficient of resistance as high as 3.45%° C.−1, which is about 60% higher than that of vanadium oxide that has been widely used as the detector material in the conventional microbolometers. This detector structure allows dual band uncooled or moderately cooled operation. In the case of the use of PbSe as the detector material, largely enhanced MWIR operation is enabled over a standard uncooled micro-bolometer tuned to the LWIR, and high temperature dual band MWIR and LWIR operation is enabled as compared to quantum well or HgCdTe detectors that must be cooled to cryogenic temperatures.

The invention relates to a sulfur-group lead-compound thermoelectric material and a preparation method thereof. The chemical formula of the sulfur-group lead-compound thermoelectric material is Pb(1-x)Sb(2x / 3)Se, wherein the x is larger than 0 and is less than 0.09. According to the preparation method, a high-purity simple substance is used as a raw material; batching is carried out based on a stoichiometric ratio in the chemical formula; after vacuum packaging, high-temperature melting, and annealing heat treatment are carried out, grinding is carried out to obtain powder; vacuum hot pressing sintering and slow cooling are carried out to obtain a sheet type block material that is a lead selenide material based on target components. A controllable preparation method of forming a dislocation structure by introducing a Pb positive ion vacancy structure is designed; and because a high-density transgranular dislocation structure is introduced into the material, intermediate-frequency phonons can be scattered effectively, so that the lattic thermal conductivity, less than 0.4W / m-K, of the material, can be reduced substantially. According to the prepared novel high-performance thermoelectric material based on Pb(1-x)Sb(2x / 3)Se, the zT value reaches 1.6 on the condition of 900K, wherein the zT value is a highest value of the existing PbSe system terminal. Therefore, the sulfur-group lead-compound thermoelectric material is a novel thermoelectric material with great large-scale application potential.

The invention relates to a method of processing non-refrigerated lead selenide infrared detectors, consisting in: 1) selecting the substrate and preparing same; 2) delineating and depositing multilayer interference filters; and 3) treating polycrystalline lead selenide infrared detectors on the interference filters, comprising the following steps, namely 3a) metal deposition, 3b) delineation of the metal deposit, 3c) delineation of the sensor, 3d) PbSe deposition by means of thermal evaporation, 3f) processing of sensor, 3g) thermal treatment in order to sensitise the active material, and 3h) deposition of a passivator layer on the active material. The inventive method is unique in that it can be used to treat differently-shaped non-refrigerated infrared detectors on the same substrate, including discrete elements, multielements, linear matrices, two-dimensional matrices, etc., with the responses of each being modified by design by the corresponding interference filter. The invention is suitable for low-cost infrared detectors that are used for process control, gas analyses, temperature measurements, military applications, etc.

A process for preparing water-phase nano-lead selenide features the reaction between lead acetate, selenourea and coating agent chosen from mercaptoacetic acid, mercaptopropionic acid, cysteine, thioglycerin, and mercaptoethanol at 60-180 deg.C for 15-90 min.

The invention discloses a mode-locked optical fiber laser which takes a lead selenide quantum dot as a saturable absorber. Passive mode-locked optical fiber lasers based on the saturable absorbers are applied widely and gradually, bust most of existing quantum dot saturable absorbers are blocky structures, the coupling efficiency is low and the saturable absorbers are difficult to be compatible with the otpical fiber laser. The mode-locked optical fiber laser comprises a pump source, a wavelength division multiplexer, a gain optical fiber, an output coupler, a filter, an optical fiber saturable absorber and a connection optical fiber. The optical fiber saturable absorber is composed of lead selenide quantum dot-doped glass optical fiber. The pump source is a semiconductor laser with multimode tail fibers. The gain optical fiber is a ytterbium-doped optical fiber, an erbium-doped optical fiber or a thulium-doped optical fiber. The connection optical fiber is a single-mode optical fiber. According to the mode-locked optical fiber laser, the saturable absorber has higher third-order non-linear optical effect and faster time response than those of the same-component blocky material and is compatible with the mode-locked optical fiber laser.

A photoconductive bolometer infrared detector using a detector material that has a resistance changed due to photo-excitation and thermal-excitation from an incident radiation in the infrared range. The resistance changes caused by photo-excitation and the thermal excitation are additive for this detector material. The detector material is suspended over a substrate by a gap of one quarter wavelength of the incident radiation, such that the thermal absorption of the incident radiation can be enhanced. Preferably, the detector material is lead selenide that has a thermal coefficient of resistance as high as 3.45%° C.−1, which is about 60% higher than that of vanadium oxide that has been widely used as the detector material in the conventional microbolometers. This detector structure allows dual band uncooled or moderately cooled operation. In the case of the use of PbSe as the detector material, largely enhanced MWIR operation is enabled over a standard uncooled micro-bolometer tuned to the LWIR, and high temperature dual band MWIR and LWIR operation is enabled as compared to quantum well or HgCdTe detectors that must be cooled to cryogenic temperatures.

The invention discloses a quantum dot hybrid transparent polyimide fluorescent film and a preparation method. The quantum dot hybrid transparent polyimide fluorescent film comprises 0.0001-2.0wt% of quantum dots, 85-99wt% of polyimide and 0-5wt% of additive. The quantum dots are one or more of carbon quantum dots, silicon quantum dots, germanium quantum dots, cadmium sulfide quantum dots, cadmiumselenide quantum dots, cadmium telluride quantum dots, zinc selenide quantum dots, lead sulfide quantum dots, lead selenide quantum dots, indium phosphide quantum dots and indium arsenide quantum dots. Polyimide is prepared by polymerization and imidization reaction of alicyclics, a fluorine-containing bifunctional (multifunctional) organic acid anhydride monomer and an organic amine monomer. Thequantum dot hybrid polyimide fluorescent film has high light transmittance, high quantum efficiency, low dielectric constant and loss and can be applied to the technical field of LED (light-emitting diode) luminescence and display.

The invention discloses a method for preparing lead selenide nanocrystals. The method comprises the following steps of: putting selenium powder in a container; removing the air from the container and filling the container with inert gas; adding alkylamine which has a long chain with a boiling point of over 180 DEG C into the container; fully stirring and heating the selenium powder and the ammonia to perform full reaction so as to form ligand; adding lead chloride into the alkylamine which has the long chain with the boiling point of over 180 DEG C, fully stirring the mixture, vacuuming the container and then heating the mixture of the lead chloride and ammonia to fully dissolve the lead chloride in the ammonia; and injecting the mixture of selenium powder into the mixture of lead chloride to perform reaction so as to obtain the lead selenide nanocrystalline particles.

An improved infrared-based gas detector apparatus is described in which a substantial improvement in temperature measurement and tracking accuracy is achieved by combining a temperature sensing element such as a Thermistor to the body of a Lead Selenide (PbSe) plate detector. This allows for as close to possible measurement of the actual Lead Selenide film temperature without coming directly in physical contact with the film surface itself.

Semiconductor materials offer several potential benefits as active elements in the development of harvesting-energy conversion technologies. In particular, lead selenide (PbSe) semiconductors have been used and proposed to design solar energy harvesting devices, IR sensors, FET devices, amongst others. The present disclosure provides a simple, low cost synthesis of lead selenide using benzoic acid as the capping ligand in an opened environment. The use of an aromatic ligand, and mores specifically benzoic acid, provides robustness and more durability to the lead selenide, and therefore prevents the lead selenide from breaking or cracking easily. Also the aromatic ligand prevents the degradation and oxidation of the lead selenide, without affecting any of the lead selenide electronic and chemical characteristics.

The invention provides a method for preparing a lead selenide polycrystalline film on the basis of oxygen ion beam assisted deposition. In order to solve the problem of incapability of accurately controlling the oxygen doping amount and depth distribution in the PbSe film preparation process by physical vapor deposition-atmosphere annealing combination, oxygen ion assisted surface bombarding is performed by an ion beam assisted deposition technique in a static mixing mode after the film growth finishes, and the film is subjected to subsequent vacuum annealing to prepare the PbSe polycrystalline film with favorable and stable photosensitivity. The method can accurately control the oxygen ion injecting amount and depth distribution, and separates the oxygen doping from the polycrystallization process, thereby enhancing the degree of freedom of process optimization. The preliminary characterization of optical I-V characteristic, SEM (scanning electron microscope), XRD (X-ray diffraction) and the like on the prepared sample indicates that the PbSe polycrystalline prepared by the method has favorable photoelectric properties and surface characteristics.

Method to process polycrystalline lead selenide infrared detectors consisting in: 1) Substrate preparation; 2) Metal deposition; 3) Metal delineation; 4) Sensor delineation; 5) PbSe deposition by thermal evaporation in vacuum; 6) Specific thermal treatment for sensitizing the active material; 7) Deposition of a pasivating layer on the active material. The method is superior to other techniques because permits to process single element detectors, multielement detectors with different geometries such as: linear arrays, 2-dimensional arrays, detectors on interference filters, multicolor arrays and devices monolithically integrated with a ROIC. Applications include low cost infrared detectors for process control, gas analysis, defense, temperature measurement etc.

The invention discloses a mode-locked fiber laser taking a lead selenide quantum dot as a gain medium. An existing mode-locked fiber laser is limited by the grain medium, only can radiate a certain special wavelength and cannot radiate some special wavelengths, The mode-locked fiber laser comprises a grain fiber, a pumping source, a wavelength division multiplexer and a modulation unit, wherein the grain fiber employs glass fiber doped with the lead selenide quantum dot, the modulation unit employs an acoustic optical modulator or graphene, and the mass percent of the lead selenide quantum dot in the grain fiber accounts for 5.68%. The mode-locked fiber laser is achieved by employing two schemes, wherein a first scheme also comprises a high reflection unit and a low reflection unit, and a second scheme also comprises a pumping isolator and an output coupler. The lead selenide quantum dot is used as the gain medium of the laser, and the mode-locked fiber laser can radiate laser with the special wavelength being 1,700 nanometers by means of the characteristic of dependence of quantum dot irradiation wavelength on size and by combining the advantage of large emission cross section of the lead selenide quantum dot.

The embodiment of the invention discloses a saturable absorption device, a preparation method and an optical fiber pulse laser. The saturable absorption device comprises an optical element and a saturable absorption film, wherein the saturable absorption film is disposed in the optical transmission path of the optical element; and the saturable absorption film comprises lead selenide. The saturable absorption device provided by the embodiment of the invention utilizes the saturable absorption characteristics of lead selenide to compress the continuous laser into pulsed laser, which has the characteristics of good photoconductive effects and sensitive response, and can be stably generated Q-switched or mode-locked laser pulses when mounted in an optical fiber laser.

The invention belongs to the field of photoelectronic devices, and particularly relates to a composite-structure lead salt film for infrared photoelectricity and a preparation method thereof. The leadsalt film comprises a base, a lead salt crystal grain layer prepared by a physical vapor deposition method, and small-crystal-grain lead salt prepared by a chemical method; the lead salt crystal grain layer covers the base, and gaps exist among lead salt crystal grains; the small-crystal-grain lead salt is embedded into the gaps; the lead salt film is lead sulfide or lead selenide; and the base is a quartz substrate or a sapphire substrate or a silicon wafer containing an oxide layer. The preparation method comprises a physical vapor deposition method and a chemical method. The composite structure lead salt film provided by the invention is more compact in structure and high in uniformity; as a photoelectric detector, the annealed composite structure lead salt film is low in noise, high in specific detection rate, short in time consumption of the preparation method and simple in process.

The invention provides a preparation method of a lead selenide semiconductor film. The method mainly solves problems of loose film tissue and weak bonding strength with matrix of a film prepared by a traditional chemical method, and also solves problems of lack of photoelectric performance of the film prepared by a traditional chemical method and subsequent sensitization process required. The method employs a non-equilibrium radio frequency magnetron sputtering system and a lead selenide composite target material to prepare a coating; oxygen is introduced during a preparation process; and oxygen flow and sputtering power are adjusted to realize control on the film performance. The compact coating prepared by the invention has good combination performance between the film and the matrix, and good photoelectric response performances. The method is easily practical, uses simple and easily available raw materials and is easy to realize industrialized production.

A sensor device to detect a level of carbon dioxide in a body of gas includes one or more lead selenide detectors as infrared sensing elements. The sensor device operates without temperature regulation required by conventional lead selenide-based sensors, and instead measurements of the sensor device are compensated for a temperature measured by a thermal sensor.

The invention provides a lead selenide coated lead telluride dendritic crystal composite and a preparation method thereof, and relates to a thermoelectric material. The lead selenide coated lead telluride dendritic crystal composite and the preparation method provided by the invention have the advantages that the preparation method is low in reaction temperature, simple in process and friendly to environment, and the synthesized powder is high in purity and good in morphology. The lead selenide coated lead telluride dendritic crystal composite is composed of lead telluride and lead selenide, wherein PbTe in a stoichiometric proportion is coated with PbSe in a stoichiometric proportion. The preparation method comprises the steps that Pb(CH3COO)2.3H2O, TeO2 and SeO2 are dissolved in a sodium hydroxide aqueous solution in the mol ratio of Pb: Te: Se=2: 1: 1; NaBH4 is added to the solution and mixed together to obtain a precursor solution; next, the precursor solution is transferred into a reaction kettle and preserved with heat for 18-22 h at a temperature ranging from 160 to 200 DEG C and then the reaction is stopped; after the reaction temperature is reduced to the room temperature, precipitate is separated out, washed until neutrality and dried at a constant temperature; finally, the lead selenide coated lead telluride dendritic crystal composite is obtained.

The invention discloses a method for inhibiting a quantum dot surface defect state based on crystal face control, and belongs to the technical field of preparation of compound semiconductor nano materials; the method includes heating the lead precursor solution to 40 DEG C to 70 DEG C, and then rapidly injecting a sulfur source or selenium source solution with the concentration of 0.6 mol / L to 0.8mol / L; slowly dropwise adding a sulfur source or selenium source solution with the concentration of 0.1 mol / L-0. 2mol / L; then adding a ligand, then adding an anti-solvent until the solution becomes turbid, then centrifuging, and precipitating to obtain lead sulfide quantum dots, lead selenide quantum dots, lead sulfide / lead selenide core-shell quantum dots or lead selenide / lead sulfide core-shellquantum dots which are wrapped by the ligand and have a body-centered tetragonal lattice structure, wherein the amount of substance of the lead precursor is greater than the sum of the amount of substance of the added sulfur source or selenium source, and the whole reaction is carried out under protective gas. The final product can effectively relieve the exposure condition of the {100} crystal face, avoids invasion of oxygen and moisture, has few surface defect states, and has good stability in air.

The invention discloses a preparation method for a quantum dot photoelectric detector, and the preparation method comprises the following steps: preparing a precursor solution containing a cadmium selenide colloidal quantum dot; preparing a lead selenide colloidal quantum dot solution based on the precursor solution; removing impurities in the lead selenide colloidal quantum dot solution and performing separation to obtain a lead selenide colloidal quantum dot material; providing a substrate, and setting a plurality of spaced electrodes on the surface of the substrate; placing the lead selenide colloidal quantum dot material on the surface of the substrate to form a quantum dot photosensitive layer and electrically connecting the photosensitive layer to the electrode. The invention also provides the quantum dot photoelectric detector.

The invention provides a lead selenide quantum dot / graphene composite material and a preparation method thereof. The composite material is prepared with graphene oxide sheets as a hard template through an ionic complexing method. Firstly, through the complexing and electrostatic effects between carboxylic groups in the graphene oxide and soluble lead salt, lead ions are immobilized on the surface of the graphene oxide, and then a less amount of an alkaline solution is dropwisely added slowly, wherein a certain interval is maintained between graphene oxide sheets through electrostatic repulsion between hydroxide ions and carboxylate ions. A selenium precursor solution is prepared under protective of nitrogen and then is added to the graphene oxide / lead ion complex to to be in a reflux reaction. A reduction agent is then added to reduce the graphene oxide sheets to prepare the lead selenide quantum dot / graphene composite material. The method is simple in operation, is convenient to operate and is repeatable. The composite material has high electron transportation performance of graphene, is high in Seebeck coefficient, and has excellent application prospect in the field of thermoelectricity.

The invention discloses a lead selenide nanorod, a preparation method and application thereof in a field effect transistor. The preparation method includes: using lead selenide and trans-2-caproleic acid as raw materials to prepare a lead precursor; performing reaction and aftertreatment to obtain the lead selenide nanorod. A molecular formula is PbSe, a surface ligand is organic acid-trans-2-caproleic acid, and band gap is 1.03 electron volt. The lead selenide nanorod is applied to the field effect transistor, an inorganic ligand-tetrabutylammonium halide is enabled to exchange an organic acid ligand on the surface of the lead selenide nanorod, electrical performance of the lead selenide nanorod shows bipolarity, electron mobility measured in vacuum is 0.1cm2 / Vs, and hole mobility is 1.1x10-4cm2 / Vs. in 50-297K heterotherm, charge transfer mechanism at 200K is changed from nearest transition mechanism into transition mechanism in a variable area, charge transmission is dominated by a highly-disorderly state, and the lead selenide nanorod can be widely applied in the field of solar cells and photoelectric detectors.

The invention discloses a PbSe quantum dot medium-long wave infrared photoelectric detector based on in-band transition, and a manufacturing method thereof. PbSe nanometer colloid shows a good exciton structure, and energy exciton tuning ranges from 0.5 eV to 1 eV, which is a size function. When band-edge fluorescence is observed from 1.2 m to 24 m, the Stokes shift is small, and the sub-ns service life is close to the unified quantum yield. During 1.064 nm pumping, first exciton attenuation is consistent with radiation relaxation under low pumping intensity and Auger recombination under high pumping intensity. Optically induced absorption is observed at approximately the middle gap. Lead selenide (PbSe) quantum dots have the characteristics of wide infrared spectrum regulation and control range, high fluorescence quantum yield, solution processability and the like, and coating of a shell layer is one of strategies for effectively improving optical characteristics and chemical stability of the PbSe quantum dots and is a research direction for promoting application and development of the PbSe quantum dots. The PbSe core-shell quantum dots designed by the invention have very high application value in the fields of photoelectric detection, solar cells, lasers, photocatalysis and the like.

An iris imaging system is provided. The iris imaging system includes at least one light source configured to illuminate an iris at a spectrum of light. The iris imaging system also includes at least one image capturing device including at least one of an indium-gallium-arsenide, lead sulphide, and lead selenide based detector and configured to capture an image of the iris via light reflected from the iris at the spectrum. The device is further configured to provide a signal representing one or more features of the iris in response to the light reflected from the iris.

The invention provides a flexible antimony selenide solar cell and a preparation method thereof. According to the method, a lead selenide back contact layer is prepared on a back electrode through a low-temperature magnetron sputtering method, then subsequent preparation of an antimony selenide absorption layer, a buffer layer, a window layer and a top electrode is carried out, crystal growth of subsequently deposited antimony selenide is optimized through the lead selenide back contact layer, meanwhile, the contact barrier of a back contact interface is reduced, and the service life of the back contact interface is prolonged. And the preparation of the flexible, low-temperature and efficient antimony selenide thin film solar cell is realized. The invention provides a novel preparation method of the low-temperature flexible back contact layer, effectively optimizes the growth of the antimony selenide absorption layer, reduces the back contact potential barrier of the device, improves the performance of the device, and realizes the preparation of the flexible antimony selenide solar cell.

The invention belongs to the technical field of infrared detection, and relates to a method for preparing a lead selenide film by using a microwave plasma chemical vapor deposition technology. The method comprises the following steps: (1) growing a lead selenide film on a substrate by adopting a thermal evaporation technology; and (2) treating the lead selenide film by adopting the microwave plasma chemical vapor deposition technology. The microwave plasma treatment technology does not cause selenium element loss, and does not change element composition or material properties of raw materials,the crystallization degree is improved only through the sintering phenomenon, and the photoelectric property is enhanced.