65 results about "Low energy photons" patented technology

A photovoltaic cell to convert low energy photons is described, consisting of a p-i-n diode with a strain-balanced multi-quantum-well system incorporated in the intrinsic region. The bandgap of the quantum wells is lower than that of the lattice-matched material, while the barriers have a much higher bandgap. Hence the absorption can be extended to longer wavelengths, while maintaining a low dark current as a result of the higher barriers. This leads to greatly improved conversion efficiencies, particularly for low energy photons from low temperature sources. This can be achieved by strain-balancing the quantum wells and barriers, where each individual layer is below the critical thickness and the strain is compensated by quantum wells and barriers being strained in opposite directions minimizing the stress. The absorption can be further extended to longer wavelengths by introducing a strain-relaxed layer (virtual substrate) between the substrate and the active cell.

A CMOS-compatible FET has a reduced electron affinity polycrystalline or microcrystalline SiC gate that is electrically isolated (floating) or interconnected. The SiC material composition is selected to establish the barrier energy between the SiC gate and a gate insulator. In a memory application, such as a flash EEPROM, the SiC composition is selected to establish a lower barrier energy to reduce write and erase voltages and times or accommodate the particular data charge retention time needed for the particular application. In a light detector or imaging application, the SiC composition is selected to provide sensitivity to the desired wavelength of light. Unlike conventional photodetectors, light is absorbed in the floating gate, thereby ejecting previously stored electrons therefrom. Also unlike conventional photodetectors, the light detector according to the present invention is actually more sensitive to lower energy photons as the semiconductor bandgap is increased.

A detector array for an imaging system may exploit the different sensitivities of array pixels to an incident flux of low energy photons with a wavelength falling near the high end of the range of sensitivity of the semiconductor. The detector array may provide the de-multiplexable spatial information. The detector array may include a two-terminal multi-pixel array of Schottky photodiodes electrically connected in parallel.

The invention discloses a fluorescent material with an ultrahigh quantum yield and an application of the fluorescent material, belongs to the technical field of lighting, and particularly relates to a down-conversion fluorescent material and the application thereof, with an ultrahigh quantum yield, cooperatively absorbed by high-energy photon of lighting clusters composed of three or more Yb3+ions and discretely transmitted by a plurality of low-energy photons. The fluorescent material is composed of inorganic substrate materials and lanthanide-based ytterbium ion Yb3+ions which is doped in the inorganic substrate materials in the form of the clusters, and the molar concentration of the Yb3+ions is calculated to be from 0.01% to 20% on the basis that the sum of the molar concentration of whole metal positive ions is 100%. The number of the Yb3+ions in the clusters is three, four, five or more. The fluorescent material can be applied to improve photoelectric conversion efficiency of solar cells, and reduce ultraviolet irradiation intensity and photovoltaic cell thermalization loss.

The invention relates to a twinkled activity indicator belonging to the field of nuclear technique applications and measuring instruments. The activity indicator contains a probe bracket, the partial pressure resistance is mounted on the bracket, and the photomultiplier is mounted on the partial pressure resistance, the scintillator is mounted on the photomultiplier, under the bracket there are signal output connections which connect with the anode of photomultiplier and high pressure connections which connect with photomultiplier via the partial pressure resistance. Because the detecting head is scintillation crystal not the ionization chamber with thick wall, the energy-limiting valve of testing nuclide and the work voltage can be dropped, the alpha, beta charged particles can be detected, and the efficiency of detecting the low energy photon nuclide can be improved. Because of the photomultiplier, the pulsing signals can be measured, and the sensibility of the detecting head can be improved. According to the kinds of the nuclides, you can choose detector with different crystals that it can drop the cost, and it is economic and practical for medium-sized, pint-sized or county hospitals.

The invention discloses an up-conversion solar cell, relating to a solar cell. The up-conversion silicon solar cell is a nano up-conversion luminescence layer (3) prepared with nano up-conversion luminescent materials by the method of carrying out spin coating or screen printing on the back surface of the silicon solar cell (2); sunlight (1) comes in from the front of the silicon solar cell (2). The materials of the nano up-conversion luminescence layer (3) are silicon dioxide-lanthanum fluoride nanocrystalline glass ceramics doped with erbium ions, or silicon dioxide-lanthanum fluoride nanocrystalline glass ceramics doped with both erbium ions and ytterbium ions or zinc sulfide doped with erbium ions. The nano luminescence layer is 0.5-2um thick. The up-conversion silicon solar cell can convert the low-energy photons which can not be effectively absorbed by the silicon solar cells to the high-energy photons which the silicon solar cells can respond to, thus expanding the spectral response range of the solar cells, improving the service efficiency of sunlight in unit area and lowering the cost.

A CMOS-compatible FET has a reduced electron affinity polycrystalline or microcrystalline SiC gate that is electrically isolated (floating) or interconnected. The SiC material composition is selected to establish the barrier energy between the SiC gate and a gate insulator. In a memory application, such as a flash EEPROM, the SiC composition is selected to establish a lower barrier energy to reduce write and erase voltages and times or accommodate the particular data charge retention time needed for the particular application. In a light detector or imaging application, the SiC composition is selected to provide sensitivity to the desired wavelength of light. Unlike conventional photodetectors, light is absorbed in the floating gate, thereby ejecting previously stored electrons therefrom. Also unlike conventional photodetectors, the light detector according to the present invention is actually more sensitive to lower energy photons as the semiconductor bandgap is increased.

A composite target is provided and is interacted with an electron to generate an X-ray, and an energy of the electron can be changed by controlling a tube voltage at least. The composite target includes a target body and an interposing layer which is connected with the target body. The interposing layer moves a highest peak of an energy spectrum of the X-ray toward a high energy direction. The interposing layer may be a single metal or a metal mixture. Not only a low energy photon of the X-ray can be filtered by the interposing layer, but also a distribution of the low energy photon of the X-ray can be increased by increasing a thickness of the interposing layer. As the tube voltage is enhanced, an amount of a high energy photon of the X-ray generated is dramatically increased. An X-ray tube containing the above composite target is also provided.

Photoelectric systems combining a semiconductor and a phosphorescent compound with an emission spectrum of photons with energy levels equal to or greater than the activation energy of the semiconductor, wherein the phosphorescent compound is characterized by the emission spec-tram being produced by excitation of the phosphorescent compound with lower energy photons and the separation distance between the semiconductor and the phosphorescent compound is less than the distance at or above which scattering losses predominate. Methods are that embody technological applications of the photoelectric systems are also disclosed, as well as articles that embody technological applications of the photoelectric systems.

The present invention generally relates to composition and methods for downconverting light. In some embodiments, the composition and methods comprise an organic material, a nanocrystal, and a ligand capable of facilitating energy transfer between the organic material and the nanocrystal. In certain embodiments, the nanocrystal has a first excited energy state with an energy less than a triplet energy state of the organic material. The organic material, in some embodiments, may be aromatic and / or include one or more pi-conjugated carbon-carbon double bonds. In some cases, incident light may be absorbed by the organic material to produce two triplet excitons. The triplet excitons may then transfer to the nanocrystal via the ligand, where they can undergo recombination, resulting in the formation low energy photons.

A photodiode for detection of preferably very long wavelength infrared radiation wherein low energy photons are absorbed in one region and detected in another. In one example embodiment, an absorbing P region is abutted with an N region of lower doping such that the depletion region is substantially (preferably completely) confined to the N region. The N region is also chosen with a larger bandgap than the P region, with compositional grading of a region of the N region near the P region. This compositional grading mitigates the barrier between the respective bandgaps. Under reverse bias, the barrier is substantially reduced or disappears, allowing charge carriers to move from the absorbing P region into the N region (and beyond) where they are detected. The N region bandgap is chosen to be large enough that the dark current is limited by thermal generation from the field-free p-type absorbing volume, and also large enough to eliminate tunnel currents in the wide bandgap region of the diode.

A photovoltaic device comprises an upper cell and a lower cell separated by an electrically insulating layer. The cells and the layers are fabricated as a single monolithic structure, and separate electrical contacts are provided for the upper and lower cells to allow independent extraction of current from each cell. The upper cell has a larger bandgap than the lower cell so that incident low energy photons unabsorbed and unconverted by the upper cell can propagate through to the lower cell for conversion. The two bandgaps can be selected to accommodate spectral' ranges of interest. The device is incorporated into a system including two sources of photons with different wavelength ranges associated with the bandgaps of the two cells, such that each cell can convert photons from one source. One source may be the sun and the other may be a local photon source such as a thermal source. Alternatively, both photon sources may be local sources. Operation of the device can be further optimised and extended by configuring the upper cell as a tandem cell or in a MIMS arrangement, or both.

The invention belongs to a low-energy photon brachytherapy system with robot in the medical equipment field. The low-energy photon brachytherapy system comprises an imaging system, a six-degree-of-freedom robot treatment bed, a six-degree-of-freedom surgery robot and a planning software system. The imaging system is a C-arm imaging system or / and a non-X-ray source detector system. The six-degree-of-freedom robot treatment bed is formed by connection of a treatment bed support arm and a bed surface. The six-degree-of-freedom surgery robot consists of a surgical robotic mobile device, a surgical robotic arm, a low-energy photon ray source and a source adapter that are connected successively. According to the low-energy photon brachytherapy system provided by the invention, defects that a dosage cold point exists in existing brachytherapy and the applicability of the therapeutic equipment is low can be overcome. With the brachytherapy system, the treatment dosage design can be optimized; irradiation becomes accurate; dosage cold points are eliminated; the operation becomes simple; and the safety and reliability are high. The low-energy photon brachytherapy system is suitable for clinic treatment of tumors of primary hospitals.

The invention provides a solar battery module comprising a solar battery cell, a wavelength conversion film, a glass layer and a rear panel, wherein the wavelength conversion film is manufactured on the solar battery cell; the glass layer is placed on the solar battery cell; and the rear panel is placed on the back face of the solar battery cell. The battery module utilizes the wavelength conversion film to change a solar spectrum so as to improve the efficiency of a solar battery. The wavelength conversion film is a rare-earth composite and has the function of converting high-energy photons including near-ultraviolet light, blue light and the like into one or more low-energy photons, such as green light, near-infrared photons and the like, so as to improve the efficiency of the solar battery. The absorption range of the wavelength conversion film is 200-500 nm and the emission range is 500-1100 nm. The thickness of the wavelength conversion film is in the range of 100 nanometers to 5 microns. The battery module also can utilize a DBR (Distributed Bragg Reflector) and / or an inversed-pyramid suede structure to reduce the reflectivity and improve the efficiency of the solar battery.

The invention discloses an imaging method used for X-radiography. The imaging method comprises the following steps of: setting a special shape aluminum filter at the central position of a light source of an X-ray machine when an X-ray machine and an X-ray detector are utilized to carry out mammography, absorbing low-energy photons sent by the X-ray machine by the special shape aluminum filter, reducing the quantity scope of received photons on the X-ray detector, and adjusting the X-ray intensity and the regional quantity of different positions of a breast model region, wherein the thickness of the special shape aluminum filter is gradually increased from the center to the external edge. The imaging method can reduce the quantity scope of the received photons on the X-ray detector, adjust the X-ray intensity and the regional quantity, and enhance the imaging quality.

The invention discloses a three-junction cascade solar battery which comprises a Ge battery of a bottom layer, an InGaAs battery of a middle layer and an (Al) GaInP battery of a top layer. In(Ga)As quantum dots are embedded in the InGaAs battery of the middle layer. The invention further discloses a manufacturing method of the three-junction cascade solar battery. The In(Ga)As quantum dots are embedded in the three-junction (Al) GaInP / InGaAs / Ge batteries in traditional lattice matching, adsorption of low-energy photons and separation of carriers are performed by quantum dot materials, the interlayer coupling of the quantum dots is fully utilized, the physical mechanism that the density of the quantum dots influences quantum efficiency and solar battery photoelectric conversion efficiency is utilized to achieve effective combination of a traditional multijunction structure and a novel quantum dot structure, band gap design and regulation of a three-junction battery in photocurrent matching are achieved, adsorption of sunlight low-energy spectra is achieved to the largest extent, and accordingly conversion efficiency of the three-junction cascade solar battery is improved.

A detector array for an imaging system may exploit the different sensitivities of array pixels to an incident flux of low energy photons with a wavelength falling near the high end of the range of sensitivity of the semiconductor. The detector array may provide the de-multiplexable spatial information. The detector array may include a two-terminal multi-pixel array of Schottky photodiodes electrically connected in parallel.

In some embodiments, without limitation, the invention comprises a modulated image-guided x-ray brachytherapy system including a source providing low-energy photons, the source configured for placement at least partially within a patient, a control system configured to modulate the source, and an imaging systems for locating the source relative to a treatment location in the patient. The system may further comprises a target at least partially within the patient, a generator located outside the patient for providing low-energy photons, the generator configured to direct low-energy photons to the target, and a conduit between the generator and the target providing a path for the low-energy photons to travel inside the patient. The system may further comprise an in situ x-ray generator for insertion within the patient. The system may further comprise a radioactive pellet.

Transmission of low energy light is one of the primary loss mechanisms of a single junction solar cell. Molecular photon upconversion via triplet-triplet annihilation (TTA-UC)—combining two or more low energy photons to generate a higher energy excited state—is an intriguing strategy to surpass this limit. The present disclosure is directed to self-assembled multilayers, e.g., bi- or trilayers, on metal oxide surfaces as a strategy to facilitate TTA-UC emission and demonstrate direct charge separation of the upconverted state. A three-fold enhancement in transient photocurrent is achieved at light intensities as low as two equivalent suns. The multilayer structure comprises a substrate comprising a metal oxide surface and a bulk region, and a self-assembled bilayer film, the bilayer film comprising: (a) an acceptor molecule covalently bonded to the metal oxide surface; (b) a linking metal ion bonded to the acceptor molecule; and (c) one or more sensitizer molecule(s) bonded to the linking co-ordinating metal ion.

The invention discloses Eu3+ / Yb3+ doped silicate glass-ceramics and a preparation method and application thereof. The glass-ceramics are doped with Eu3+ / Yb3+, and contained crystals are hexagonal-phase Ba4La6O(SiO4)6. The glass-ceramics are simple in crystal phase composition, crystallization is easy to control, the glass forming capability is good, raw materials required for synthesis are easy to obtain, the volatilization quantity is less than fluorides during melting, and the glass-ceramics have small harm to human health and environment. The glass-ceramics can convert high-energy shortwave photons (300-480 nm) absorbed by Eu3+ into low-energy photons of about -1100 nm, can be used for improving the efficiency of silicon-based solar cells and have good application prospect by serving as a down-conversion luminescent material.

An energy storage device capable of combining photochemistry with thermochemistry comprises a solar condenser, a light ray frequency divider, a photochemical reactor and a thermochemical reactor, wherein the solar condenser is used for concentrating sunlight; the light ray frequency divider divides the light concentrated by the solar condenser into two beams; photons which are separated by the light ray frequency divider and participate in a photochemical reaction are guidedinto the photochemical reactor to enable photochemical reactants in the photochemical reactor to be isomerized, and energy is stored in chemical bonds; and photons which are separated by the light ray frequency divider and do not participate in the photochemical reaction are guidedinto the thermochemical reactor to enable thermochemical reactants in the thermochemical reactor to be subjected to a thermochemical reaction, and energy is stored in chemical energy. The energy storage device capable of combining photochemistry with thermochemistry respectively utilizes the photons, with different frequencies, of solar energy, high-energy photons undergo the photochemical reaction, the optical energy is directly stored in the chemical bonds, low-energy photons enter the thermochemical reactor and are firstly converted into thermal energy and then converted into chemical energy to be stored, and full spectrum efficient energy storage is realized.

The invention discloses a quantum dots based luminescent solar concentrator (QDs-LSC) based on a spectral down-conversion technique, a flat concentrating photovoltaic device and a preparation method thereof. The QDs-LSC comprises a quantum dots based luminescent solar concentrating layer, and is characterized in that the upper surface of the quantum dots based luminescent solar concentrating layer is provided with a solar spectrum down-conversion layer; the lower surface of the quantum dots based luminescent solar concentrating layer and the upper surface of the solar spectrum up-conversion layer are provided with light-trapping layer glass pieces; the upper surface of the upper light-trapping layer glass piece is provided with a top antireflection layer for reducing the reflection of sunlight; and the lower surface of the lower light-trapping layer glass piece is provided with a bottom metal reflective layer. The flat concentrating photovoltaic device comprises solar panels arranged around the QDs-LSC. PCBs plated with conductive metal are fixedly disposed on the outer sides of the solar panels. The QDs-LSC can reduce the incident photon reflection loss and low-energy photon transmittance, thereby significantly improving the photon collection efficiency in the infrared band.

An extremely non-degenerate two photon absorption (END-2PA) method and apparatus provide for irradiating a semiconductor material substrate simultaneously with two photons each of different energy less than a bandgap energy of the semiconductor material substrate but in an aggregate greater than the bandgap energy of the semiconductor material substrate. A ratio of a higher energy photon energy to a lower energy photon energy is at least about 3.0. Alternatively, or as an adjunct, the higher energy photon has an energy at least about 75% of the bandgap energy and the lower energy photon has an energy no greater than about 25% of the bandgap energy.

The present invention includes upconversion materials such as lanthanide-sensitized oxides that are useful for converting low-energy photons into high-energy photons. Because silicon-based solar cells have an intrinsic optical band-gap of 1.1 eV, low-energy photons having a wavelength longer than 1100 nm, e g., infrared photons, cannot be absorbed by the solar cell and used for photovoltaic energy conversion. Only those photons that have an energy equal to or greater than the solar cell's band gap, e.g., visible photons, can be absorbed and used for photovoltaic energy conversion. The oxides described herein transform photons having an energy less than the energy of a solar cell's band gap into photons having an energy equal to or greater than the energy of the band gap. When these oxides are incorporated into a solar cell, they provide more photons for photovoltaic energy conversion than otherwise would be available in their absence. Nearly 10% of the infrared photons incident on these oxides are upconverted into visible photons. This upconversion efficiency is more than twice as large as the upconversion efficiency for NaYF4-based upconversion materials. The solar radiation energy conversion efficiency of a silicon-based solar cell will increase by 1.8% or greater by including the oxides described herein because they allow the solar cell to absorb and use are larger portion of the solar spectrum for photovoltaic energy conversion.

The invention discloses a high-light-transmittance photovoltaic packaging material adopting a nucleating antireflection agent. The photovoltaic packaging material is prepared by performing the steps of premixing, melt extrusion, casting film formation, cooling, slitting, winding and the like on photovoltaic packaging material matrix resin, graft modified matrix resin, the nucleating antireflectionagent and other auxiliary agents; by adding the nucleating antireflection agent with quantum dot nanoparticles into a packaging material system, on the one hand, the crystallization behavior of crystallizable polymer chain segments in resin structures is changed, the crystallization rate is accelerated, the crystal density is increased, the micronization of grain size is promoted, and the grain size is smaller than the visible wavelength, thereby improving the transmittance of the photovoltaic packaging material; on the other hand, the quantum dot nanoparticles have the function of convertingshort waves into long waves, can realize the conversion of high-energy photons into a large number of low-energy photons, and have the effect of photon multiplication, so that the intensity of lightincident on a battery piece is increased, the utilization of sunlight by components is enhanced, and the photoelectric conversion efficiency of components is optimized and improved.

The invention belongs to the technical field of coal separation, and particularly relates to a waterless separator of high-sulfur coal and low sulfur coal gangue blocks and sulfur blocks. The waterless separator comprises a raw coal screening graded feed system, an elastic double-flange coal conveyor, a high-sulfur coal gangue block and sulfur block separating system, a low-sulfur conveying electronic weighing scale, a high-sulfur coal gangue block and sulfur block conveying system, an electric variable frequency speed regulating system, a programmable control type electric appliance interlocking device, a photoelectric conversion and electronic pulse filter, a detecting head shielded chamber, a 238 Pu low-energy photon source and a probe. The photoelectric conversion and electronic pulsefilter, the probe and the 238 Pu low-energy photon source form an online recognition separation detecting system of 238 Pu type coal sulfur and ash to waterlessly separate the high-sulfur coal blocks, the gangue blocks and the sulfur blocks in raw coal blocks and obtain low-sulfur low-ash refined coal, and no slime water is generated to pollute the environment, thereby greatly reducing the coal separation energy consumption and the coal separation cost.

The invention relates to a heterojunction solar cell and a preparation method thereof, and belongs to the technical field of solar cell manufacturing. Comprising a crystalline silicon substrate, and a front intrinsic amorphous silicon layer, an N-type doped layer, a front TCO layer and a front metal electrode are sequentially deposited on the front surface of the crystalline silicon substrate; a back intrinsic amorphous silicon layer, a P-type doped layer, a back TCO layer and a back metal electrode are sequentially deposited on the back of the crystalline silicon substrate, and a functional film containing a down-conversion fluorescent material covers a fine gate electrode in the front metal electrode and the front TCO layer which is not shielded by the metal electrode. By introducing the functional film containing the down-conversion fluorescent material, photons in a short-wave region which cannot be utilized by a solar cell can be converted into photon energy matched with spectral response of the photons, namely photons below 400nm are absorbed and converted into low-energy photons of 400-1100nm, so that absorption and utilization of the cell to sunlight are promoted, and the conversion efficiency of the solar cell is improved. The conversion efficiency of the heterojunction solar cell is improved, and the damage effect of part of ultraviolet light on the cell is weakened.

The invention relates to methods and means for improving the power generated, and thus efficiency of solar cells (20, 30). The best mode of the invention at present is considered to be a double or triple junction tandem solar cell (20, 30) that has one or two photon filters (100, 101) of the invention in between the solar cell layers (200, 201, 202, 203), respectively. The photon filter (100, 101, 102) is arranged to reflect photons with wavelength shorter than x and arranged to be transparent to photons of wavelength longer than x by focussing the said lower energy photons out of small area apertures (140, 141) on the other side of the photon filter (100, 101, 102) and arranging the other side of the photon filter (100, 101, 102) to reflect (150, 151) at least some of the said photons of wavelength longer than x.; By using the photon filters (100, 101, and 102) of the invention in between the solar cell layers (200, 201, 202, and 203), photons can be trapped between filters to solar cell layers at an energy at which the quantum efficiency (QE) of the solar cell layer is the best.

The present invention discloses a solar cell assembly package glue film and an application thereof. The packaging glue film is composed of a transparent organic glue film and under-spectrum conversion particles, the under-spectrum conversion particles are distributed in the transparent organic glue film, and the distribution density of the under-spectrum conversion particles increases gradually from top to bottom. The advantages of the glue film are that: the high-energy photons in the sunlight become the low-energy photons easier to absorb, at the same time, a gradual change refractive index gradient from top to bottom is formed in a solar cell assembly, and the surface reflection is reduced. According to the present invention, the high-energy photons can be utilized more effectively, the surface reflection also can be reduced, and the photoelectric conversion efficiency of the solar cell assembly is improved.