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Lithia Springs, GA, United States

Grant
Agency: Department of Health and Human Services | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 149.98K | Year: 2011

DESCRIPTION (provided by applicant): A new class of high-performance X-ray phosphor screens will be developed based on dot-in-a-rod core/shell nanorod (NR) structures embedded in transparent polymer matrices, with applications to protein crystallography, digital radiography and mammography, as well as a host of other important imaging and lighting applications. The goal is to achieve high spatial resolution, very fast time response, minimum afterglow, minimum self-absorption and excellent X-ray conversion efficiency. Our nano- composite phosphor screens will be X-ray tested by Radiation Monitoring Devices (RMD) and compared with equivalent spherical quantum dot (QD) screens and conventional micro-crystalline ZnSe:Cu,Cl and Gd2O2S:Tb phosphor screens. Although phosphor screens made from micron-sized phosphors are efficient, bright X-ray converters, their large particle size produces a great deal of scatter, which limits their spatial resolution. Preliminary theoretical and experimental studies show that nanophosphors in a transparent polymer-matrix screen exhibit significantly higher spatial resolution than micron-sized phosphor particles. Compared with spherical QDs, NR exhibits much larger Stokes shift to minimize self-absorption. In addition, their fast decay times and low afterglow characteristics will ensure response times orders of magnitude faster than existing phosphors. Moreover, to increase X-ray absorption, NR structures can be made from high-Z materials to increase X-ray absorption and their spectral emission tuned to match the spectral sensitivity of CCD sensors. Specifically in Phase I, we will prepare NR structures and related screening techniques, and quantify their X-ray photoluminescence performance. Success in Phase I will be proven if we can show that these NR structures are significantly better than existing micron-sized crystalline phosphors and conventional spherical quantum dots, in terms of spatial resolution, time resolution, and self-absorption. In Phase II, we will develop the techniques to synthesize large quantities of high quality nanocrystals, and optimize large screen characteristics for protein crystallography and medical imaging CCD detectors. NR-based X-ray converting films will have significant applications in digital radiography, crystallography, mammography, and various other biomedical imaging applications, enhancing their value to the NIH and to the molecular biology and medical communities as a whole. PUBLIC HEALTH RELEVANCE: The proposed nanorod luminescent structures will significantly enhance the performance of X-ray imaging compared to current state-of-the art. They will have applications in digital radiography, crystallography, and various medical imaging applications, enhancing their value to the NIH and to the molecular biology and medical communities as a whole.


Grant
Agency: Department of Health and Human Services | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 157.42K | Year: 2009

DESCRIPTION (provided by applicant): A new class of high-performance X-ray phosphor screens will be developed based on nanocrystal quantum dots (QDs), with applications to protein crystallography, digital radiography and mammography applications, as well as a host of other important imaging and lighting applications. The goal in this project is to maximize X-ray conversion efficiency, spatial resolution, and time response, which will minimize afterglow. Nano-composite phosphor screens will be tested in state-of- the-art crystallographic CCD detectors, and compared with standard micro-crystalline ZnSe:Cu,Cl and Gd2O2S:Tb phosphor screens. Although phosphor screens made from micron-sized phosphors are efficient, bright X-ray converters, their large particle size produces a great deal of scatter, which limits their spatial resolution. Preliminary theoretical and experimental studies show that quantum dot phosphors in a transparent polymer-matrix screen exhibit significantly higher spatial resolution than micron-sized phosphor particles. In addition, their pico- to nano-seconds decay times and low afterglow characteristics will ensure response times orders of magnitude faster than existing phosphors. Moreover, QD phosphors can be made from high-Z materials to increase X-ray absorption and their spectral characteristic tuned to match the spectral sensitivity of CCD sensors. Specifically in Phase I, we will prepare QD phosphors and related screening techniques, and quantify their X-ray photoluminescence performance. Success in Phase I will be proven if we can show that nanometer-sized crystalline phosphors are significantly better than existing micron-sized crystalline phosphors, in terms of spatial resolution and time resolution. In Phase II, we will develop the techniques to synthesize large quantities of high quality nanocrystals, and optimize large screen characteristics for protein crystallography and medical imaging CCD detectors. QD-based X-ray converting films will have significant applications in digital radiography, crystallography, mammography, and various other biomedical imaging applications, enhancing their value to the NIH and to the molecular biology and medical communities as a whole. Key Words: Xray phosphor, nano-phosphor, nanocrystals, quantum dots, protein crystallography, digital radiography, mammography, biomedical imaging. PUBLIC HEALTH RELEVANCE: The proposed nanocrystalline phosphor materials will have significant applications in digital radiography, crystallography, and various medical imaging applications, enhancing its value to the NIH and to the molecular biology and medical communities as a whole.


Grant
Agency: Department of Energy | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 149.94K | Year: 2015

Statement of the problem or situation that is being addressed - typically, one to three sentences. Solid state lighting (SSL) is a fast growing technology, which is starting to replace conventional lighting products such as fluorescent and incandescent bulbs. While the current efficiency of some commercial SSL products has surpassed those of most traditional lighting, it is still far below what the technology is theoretically capable of. The main reasons are attributed to poor light extraction and limited white spectral tunability that inhibit reaching the maximum luminous efficacy of radiation (LER). General statement of how this problem is being addressed. This is the overall objective of the combined Phase I and Phase II projects - typically, one to two sentences. We propose a new approach for maximizing the luminous efficacy of a phosphor down-converting LED system using a combination of (1) new high quantum yield (QY) red phosphor development, (2) surface plasmon resonance (SPR), and (3) enhanced light extraction efficiency using phosphor film technology. It is believed that this combinatorial approach to material development and phosphor structure optimization is the key to achieving solid state lighting with high luminous efficacies and spectral efficiency performance approaching the maximum luminous efficacy of radiation (LER), and with significantly reduced dependence on rare-earth compounds. What is planned for the Phase I project (typically, two to three sentences). Phase I will focus on demonstrating the feasibility of plasmonic-enhanced phosphor films applied to blue LEDs. This will be achieved by synthesizing various nano-metals that are known to exhibit surface plasmon resonance effects. Those metal nanostructures will be applied directly to phosphor particles using a thin layer of silica shell that can act as a spacer layer. The resulting structure will then be compared to the un-modified phosphor film in order to demonstrate >30% improved light extraction. COMMERCIAL APPLICATIONS AND OTHER BENEFITS as described by the applicant. (Limit to space provided). The proposed materials and structures have applicability not just in solid state lighting, but potentially in all existing lamp products including incandescent, tungsten-halogen, and all types of fluorescents lamps. Thus, any current application in indoor/outdoor lighting, or backlighting in portable electronics will immediately benefit from the increased energy savings. Additionally this technology can significantly enhance the performance of solar cell technologies by enhancing absorption of the solar spectrum by the solar cell. SUMMARY FOR MEMBERS OF CONGRESS: (LAYMAN'S TERMS, TWO SENTENCES MAX.) Plasmonic nanostructures will initiate new paradigms in the conservation and generation of energy. Higher efficiency lamps and solar cell technologies will be produced that will revolutionize the US lighting and solar power industries, by providing competitive technologies that will significantly reduce global energy use and environmental pollution.


Patent
PhosphorTech Corporation | Date: 2014-02-05

A light converter, and lights and displays incorporating the light converter are disclosed together with methods of making the light converter. The light converter has a substrate having a first layer of phosphor particles disposed on an area of one surface of the substrate. The first layer has a thickness of about 1 monolayer of phosphor particles, and the phosphor particles in the first layer form a uniform and dense layer. The thickness of the substrate can be between about 25 m and about 500 m in embodiments intended to be flexible and between about 0.5 mm and 2 mm in embodiments that can be formed into rigid shapes. The screen weight of the phosphor particles is between about 0.5 mg/cm


Grant
Agency: National Science Foundation | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 99.97K | Year: 2008

This Phase I Small Business Innovation Research (SBIR) research project will develop novel high brightness solid-state Light Emitting Diodes (LED) using doped quantum dots. Solid state lighting is rapidly gaining momentum as a highly energy efficient replacement technology for incandescent and eventually fluorescent lighting. However, current high brightness solid state devices suffer from reduced luminous efficiencies due to scattering, re-absorption, and thermal quenching losses inherent in conventional phosphors and standard undoped quantum dots. The proposed doped quantum dots have broad and size-tunable absorption bands, size and impurity tuned emission bands, size-driven elimination of scattering effects, and a distinct separation between absorption and emission bands. In addition, they also display the ability to maintain efficient (even improved) emissions at high temperatures similar to those experienced in today's high brightness LEDs. These new lamps will improve lighting and provide US industry with competitive technologies that will significantly reduce global energy use and environmental pollution. This technology has applicability to all LED light sources where a fluorescent color conversion layer is used. Thus, any current application, such as lighting in portable electronics, automobiles, traffic signaling, will immediately benefit from increased efficiency. The increased efficiency and use of LEDs will lead to significantly reduced energy requirements, lower levels of pollution, reduced toxic waste (e.g., Hg from fluorescent lamps) and a reduced dependence on foreign oil suppliers.

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