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.

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.

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.

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 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.

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 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.

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.