219 results about "Mercury cadmium telluride" patented technology

Methods and apparatus for effecting a non-uniformity correction of images of a scene obtained with an array of detector elements are disclosed. A first image of the scene having a first integration period is acquired using the array of detector elements. A second image of the scene having a different integration period is acquired, and a corrected image of the scene is generated by computing a difference of the images. In some embodiments, the first and second images are images of substantially identical scenes. According to some embodiments, the images are infrared images. Optionally, the corrected image is subjected to further correction using pixel dependent correction coefficients, such as gain coefficients. Exemplary image detection elements include but are not limited to InSb detector elements and ternary detector elements, such as InAlSb, MCT (Mercury Cadmium Telluride), and QWIP technology (Quantum Well Infrared Photodiodes). In some embodiments, the detector elements are cooled to a temperature substantially equal to an atmospheric boiling point of liquid nitrogen. Alternatively, the detector elements are cooled to a temperature below an atmospheric boiling point of liquid nitrogen, or any other operating temperature.

The invention belongs to the method for compounding cadmium selenide and quanta of cadmium telluride, which is: use cadmium oxide containing 2~18 carbon atom as cadmium source, selenium powder as selenium source and tellurium powder as tellurium source, and the mol ratio of cadmiumsource and selenium source or tellurium source is 5:1-1:5, dissolve the selenium and tellurium powder with tricapryl phosphine, make oleic acid, and tricapryl phosphine oxide as enveloping agent and the mol ratio of cadmium source and enveloping agent is 1:2-1:6, use benzene, toluene, cyclohexane, normal hexane and normal heptane as solvent, under the condition that the density of cadmium source is 0.001-0.015M, the temperature in autoclave is 140-180deg.C, heat them for 0.8-16 hours and obtain cadmium selenide and quanta of cadmium telluride with different sizes by changing the reaction time. The cadmium selenide and quanta of cadmium telluride has narrower size distribution which is shown as narrower shooting of fluorescence whose half-peak width of quanta of cadmium selenide is 22-33nm and that of quanta of cadmium telluride is 29-35nm.

The invention provides a preparation method for cadmium telluride. The method comprises a first synthesis and a second synthesis. The first synthesis comprises steps: tellurium and cadmium are mixed and placed in a first graphite boat; the first graphite boat is then placed in a first quartz tube; the first quartz tube is then placed in a first synthetic furnace; a first inert gas is introduced to empty air in the first quartz tube; a first multi-section heating and heat preservation process is carried out, the first inert gas is introduced in the front section and a first reducing gas is introduced in the back section; after the synthetic reaction, the first synthetic furnace is cooled to room temperature in sections, the first reducing gas is introduced in the front section and the first inert gas is introduced in the back section; first synthetics are obtained. The second synthesis comprises steps: the first synthetics are placed in a second graphite boat; the second graphite boat is then placed in a second quartz tube; the second quartz tube is then placed in a second synthetic furnace; a second inert gas is introduced to empty air in second first quartz tube; a second multi-section heating and heat preservation process is carried out, a second inert gas is introduced in the front section and a second reducing gas is introduced in the back section; after the synthetic reaction, heating is stopped, the second synthetic furnace is cooled to room temperature in sections, the second reducing gas is introduced in the front section and the second inert gas is introduced in the back section; second synthetics are obtained.

Methods are generally provided of sputtering a cadmium sulfide layer on a substrate. The cadmium sulfide layer can be sputtered on a substrate from a target in a sputtering atmosphere, wherein the target comprises about 75% to about 100% by weight cadmium, and wherein the sputtering atmosphere comprises a sulfur-containing source gas. The cadmium sulfide layer can be used in methods of forming cadmium telluride thin film photovoltaic devices.

The invention relates to a substrate material used for the growth of a mercury cadmium telluride material by a liquid phase epitaxy method. On the basis of the prior substrate material, a layer of cadmium zinc telluride single-crystal film completely matched with the lattice constant of mercury cadmium telluride is grown. The substrate material of the invention has the advantages that an epitaxial film has high lattice quality, and compositions can be flexibly adjusted according to the lattice constants of short wave, medium wave and long wave mercury cadmium telluride materials; meanwhile, the cadmium zinc telluride film has even compositions; the method adopts mature process, and has the advantages of simpler process equipment, short process cycle and low cost; and the substrate material with large area, high quality and high composition evenness can be provided for an infrared focal plane detector.

The invention relates to a graphene oxide-cadmium telluride/cadmium sulfide nano composite material and a preparation method thereof. The composite material is prepared by loading CdTe/CdS nuclear-shell quantum dot to the surface of PEI-GO by using covalent bonds. The preparation method comprises the following steps: adding the CdTe/CdS nuclear-shell quantum dot and a cross-linking agent into double distilled water, providing ultrasonic wave for 3 hours, further adding PEI-GO, performing ultrasonic reaction for 24 hours, and dialyzing, thereby obtaining the graphene oxide-cadmium telluride/cadmium sulfide nano composite material GO-CdTe/CdS. The GO-CdTe/CdS nano composite material prepared by using the method is relatively large in specific surface area, relatively good in water solubility, relatively high in fluorescence intensity and fluorescence stability, and can be used as a novel nano fluorescence probe which is applied to the fields such as photoelectricity, biosensors and biomedicine.

The invention relates to a synthetic method of admium telluride/cadmium sulfide/zinc sulfide quantum dots. An inner core is an admium telluride quantum dot and is coated by cadmium sulfide and zinc sulfide in sequence. The synthetic method for the quantum dots comprises the following steps of: firstly, preparing an admium telluride quantum dot with excellent fluorescent characteristic by hydrolyzing a sulfhydryl group; secondly, adding thiourea with a certain concentration into the reacted admium telluride solution, forming free suplfur ions released by slowly hydrolyzing and photolyzing thiourea and cadmium ion dangling bonds existing on the surface of the admium telluride quantum dot into bonds; generating a thin cadmium sulfide casing layer on the surface of the cadmium sulfide quantum dot; and finally adding a zinc acetate solution and a sodium sulfide solution into the admium telluride/cadmium sulfide quantum dots with nuclear shell structures and carrying out hydro-thermal growth in a polytetrafluoroethylene digestion tank to form the admium telluride/cadmium sulfide/zinc sulfide quantum dots. The quantum dots have the characteristics of high fluorescent strength, favorable stability, high quantum yield and low biotoxicity and are hopeful to be applied to the field of biomarkers instead of the traditional organic dye. The synthetic method has the advantages of simple process, convenience, low cost and strong operability.

Self stabilizing concentration profiles are achieved in solids. More particularly, semiconductor devices are made from n- or p-type mercury cadmium telluride (MCT) of the general formula HgxCd1-xTe where x=0.2 to 0.5 and n- or p-type zinc mercury telluride (ZMT) of the general formula ZnxHg1-xTe where x=0.4 to 0.6. Silver, incorporated as a doping impurity or applied as an evaporated spot electromigrated within the MCT or ZMT to create one or more p-n junctions, usually under the influence of a pulsed positive bias. The resulting concentration profiles of silver and opposing internal electric fields of the p-n junctions achieve a balancing equilibrium that preserves and maintains the stability of the concentration profiles. For a specific telluride composition, Hg0.3Cd0.7Te, indium is the n-type dopant of choice.

The invention discloses a metalized opening method of a mercury cadmium telluride passive film in a mercury cadmium telluride infrared detection chip. The method relates to a preparation technology of an HgCdTe infrared focal plane detector, in particular comprising the preparation of a selective etching solution of a CdTe passive film of the HgCdTe detection chip and a method for using the etching solution to carry out the metalized opening of the detector chip. The result shows that the etching solution has a high etching selective ration on CdTe and HgCdTe materials, and is stable with controllable etching speed. The opening method is a stable and convenient technology, has no effect on other surface treatment technologies, facilitates the improvement of surface properties of a device, improves technological stability and is vital to realize the application of CdTe passivation to a focal plane device.

Methods are generally provided for forming a cadmium sulfide layer on a substrate. In one particular embodiment, the method can include sputtering a cadmium sulfide layer on a substrate in a sputtering atmosphere comprising an inorganic fluorine source gas. Methods are also generally provided for manufacturing a cadmium telluride based thin film photovoltaic device.

Cadmium telluride based thin film photovoltaic devices are also generally provided. The device can include a substrate; a transparent conductive oxide layer on the substrate; a cadmium sulfide layer on the transparent conductive oxide layer; and, a cadmium telluride layer on the cadmium sulfide layer. The cadmium sulfide layer includes fluorine.

The invention discloses a graphite boat for improving the surface shape of the extended liquid-phase film of merury cadmium telluride, which is characterized in that the mercury supply tank formerly placed at front or rear of the mother liquid tank is changed to be placed right above the mother liquid tank, a channel is provided between the two tanks for communicating; the mercury steam generated by the mercury supply tank supplements mercury into the mother liquid from the top of the mother liquid tank, so that the supplementing of the mercury steam generated by the mercury supply tank becomes more even, hence the pressure above the mother liquid is more even; in addition, as the front and the rear strcuture of the mother liquid tank are similar, the temperature field surrounding the mother liquid tank becomes more even. The advantages with the invention is that the uneveness of pressure and temperature field can be removed to the max. extent, convection of mother liquid is slowed, hence the corrugation on the surface of the extended material is reduced.

The invention discloses a graphite boat for epitaxial growth of a horizontal liquid phase of a mercury cadmium telluride thin film. The graphite boat comprises an upper cover, a bottom support, a sliding strip and a mother solution tank, wherein the bottom support comprises a groove with one bottom edge and two side edges; the sliding strip and the mother solution tank are arranged in the groove; the mother solution tank is fixed at the upper end of the groove; the upper surface of the mother solution tank is leveled with the upper surfaces of the two side edges; the sliding strip is located between the mother solution tank and the bottom edge of the bottom support, and can do movement relative to the mother solution tank along the bottom edge; the upper cover is of a solid structure and covers the side edges of the bottom support and the mother solution tank; a drainage channel is arranged in the upper cover; a starting point and a finishing point of the drainage channel are located on a contact surface of the upper cover and the mother solution tank. According to the graphite boat disclosed by the embodiment of the invention, a drainage groove is formed in the upper cover, and a temperature field, gas flow, gas-phase distribution and mercury pressure in an epitaxial growth process of the horizontal liquid phase can be improved to a certain extent, so that the problems about surface appearance and thickness uniformity of the mercury cadmium telluride thin film are solved.

The invention relates to a method for preparing a high-performance mercury cadmium telluride p-n junction through ion injection. The method comprises the following steps: adopting an identical mercury cadmium telluride film as a substrate; manufacturing a plurality of mask plates; evaporating a ZnS film as blocking layers for ion injection; photo etching a corresponding ion injection region on the blocking layers to inject; and then finishing the junction process of the p-n junction. The blocking layers for the ion injection are ZnS film blocking layers with different thickness obtained through a plurality of superposition and evaporation; the ion injection dosage is the dosage of an identical ion and identical injection energy value after being optimized. The invention obtains a serial testing unit for superposing and evaporating the blocking layers with different thickness obtained on identical backing material; the process improvement of the ion injection is conducted to a photo etching entrance and exit area according to the ion injection dosage after being optimized at a time, so as to prepare the high-performance mercury cadmium telluride p-n junction and provide more convenient and quicker experimental investigation on optimizing process parameters for a solar infrared detector. The invention has the advantages of low testing cost, and time and energy conservation; and the method can be popularized and applied to the optimization study on the thickness of the ion injection blocking layer in other backing material system.

A device and method of use are provided for measuring the concentration of fatty acid methyl ester (FAME) in jet fuel to a limit of detection of 1 ppm. The device measures concentration of FAME in jet fuel via Fourier transform infrared spectroscopy (FTIR) with a spectral resolution of 1 cm⁻¹. The device can use an infrared light emitting diode (IR LED) and mercury cadmium telluride (MCT) detector in which the spectral output of the IR LED and the spectral response of the MCT detector is centered on the spectral absorbance of an ester bond, a defining spectral characteristic of FAME. Other IR LEDs with differing spectral outputs can be used to measure the presence and/or concentration of different analytes in different fluids.

The invention discloses a method for reducing the effects of ion radiation damage of a mercury cadmium telluride photovoltaic device. The method is that a mercury cadmium telluride sample after being injected with ions are defined into a hydrogen ion treatment region through lithography, and then the sample is put in an atmosphere of hydrogen ion to treat. The hydrogen ion treatment region is determined through a method of changing the area, form the size of an initial defined ion implanted region, the hydrogen ion treatment region is gradually enlarged, the current-voltage curve of the mercury cadmium telluride sample which is treated through the hydrogen in different regions is tested, and the size of the hydrogen ion treatment region is determined through observing the increasing phenomenon of a dark current under a reverse bias.

The invention relates to a high-pixel infrared focal plane array detector and a preparation method thereof. The detector comprises a mercury cadmium telluride epitaxial wafer and a read-out circuit, which are connected with each other, wherein a flip-chip bonding structure is prepared on the surfaces of the read-out circuit and the mercury cadmium telluride epitaxial wafer; a protective material layer also covers the surface of the mercury cadmium telluride epitaxial wafer; a filling adhesive or ZnS and the like can be selected as the protective material; the flip-chip bonding structure exposed outside the surface of the mercury cadmium telluride epitaxial wafer covers the mercury cadmium telluride epitaxial wafer; and the read-out circuit is connected with the mercury cadmium telluride epitaxial wafer through the flip-chip bonding structure. The problem of surface roughness of the mercury cadmium telluride epitaxial wafer is solved through planarization; the flip-chip bonding yield is improved; and meanwhile, the material stress caused by roughness in the flip-chip bonding process is avoided.

The invention relates to a method for producing a cadmium telluride or cadmium zinc telluride single crystal. The method comprises the following steps of: forming an overall temperature field including a crystal growing zone and an in-situ annealing zone; passing a crucible with a rich-tellurium material and a cadmium telluride or cadmium zinc telluride polycrystalline material through the crystal growing zone, wherein the rich-tellurium material in the crucible is molten to form a melting zone in the process, the cadmium telluride or cadmium zinc telluride polycrystalline material is gradually molten into the melting zone and cooled down and the cadmium telluride or cadmium zinc telluride single crystal is separated out; and passing the crucible through the in-situ annealing zone, wherein the cadmium telluride or cadmium zinc telluride single crystal generated in the crystal growing zone is annealed in the process so as to reduce the tellurium conclusion content of the single crystal.