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A nanocrystal is a crystalline material with dimensions measured in nanometers; a nanoparticle with a structure that is mostly crystalline. These materials are of huge technological interest since many of their electrical and thermodynamic properties show strong size dependence and can therefore be controlled through careful manufacturing processes. Nanocrystals are also of interest because they often provide single domain crystalline systems that can be studied to provide information that can help explain the behaviour of macroscopic samples of similar materials, without the complicating presence of grain boundaries and other defects. Semiconductor nanocrystals in the sub-10nm size range are often referred to as quantum dots. 
Nanocrystals made with zeolite are used as a filter to turn crude oil onto diesel fuel at an ExxonMobil oil refinery in Louisiana, a method cheaper than the conventional way. A layer of nanocrystals is used in a new type of solar panel named SolarPly made by Nanosolar. It is cheaper than other solar panels, more flexible, and claims 12% efficiency. (Conventionally inexpensive organic solar panels convert 9% of the sun's energy into electricity.) Crystal tetrapods 40 nanometers wide convert photons into electricity, but only have 3% efficiency. (Source: National Geographic June 2006) In Other words, Most nanotechnology commercialization involves colloidal nanocrystals. Colloidal nanocrystals have unique chemical and physical properties that could be utilized in many applications. Some pioneers expect to incorporate these nanoscale building blocks into products such as optical transistors, electronics and drug delivery systems to take advantage of the nanomaterials' high surface-to-volume ratio, size, sensitivity and other attributes. For instance, some futurists predict that machines could be built that position atoms into perfectly assembled products, leaving no pollution or waste. Others forecast that nanoscale robots could scour cells and eliminate signs of disease. The limiting factor in the growth of this new technology is the availability of high-quality materials with desirable properties. APPLICATIONS NANOCRYSTAL IMAGING : Bio-Medical
Semiconductor nanocrystals have numerous possibilities for biomedical applications. FOR EXAMPLE: ♦Enabling Media for Wound Repair
♦ Organic Structure Detection and Sequencing
♦ Biolabeling Agents
♦ Internal Drug Delivery -ray imaging (which includes CT-SCAN and fluoroscopy) accounts for nearly 80% of all medical imaging. The advantages of capturing and storing x-ray images digitally rather than on film are overwhelming. Digital x-ray imaging has many advantages :
(a) The images can be stored in a very compact manner without risk of loss or deterioration in quality.
(b) The images can be easily enlarged and "suspicious" areas of an image can be more easily studied.
(c) The images can be easily retrieved, and can be transmitted electronically to an expert or to another medical practitioner in the same hospital or to an insurance company for reimbursement purposes.
(d) Over a period of time, pattern recognition software can be developed to aid easy diagnosis.
(e) The expense of x-ray film and the chemicals used for development as well as the environmental problems associated with the disposal of film can be entirely avoided. Problems Associated With Digital X-ray Imaging
X-rays are a form of energy which do not fall within the visible light spectrum, and must first be converted to light in order to be recorded in either digital or analog form. X-rays used for medical imaging are scattered in all directions at two distinct points of impact: first, by the anatomical features being imaged, and then by a screen (the scintillator) which converts the x-rays emerging fromr the body into light. As at present, there is no known method to minimize the scattering of x-rays by the anatomic features being imaged. However, x-ray scattering at the second point of impact (i.e. at the scintillator) can be minimized by collimating the emerging x-rays. An other problem in x-ray imaging has been the efficient absorption and conversion of x-rays by the scintillator before the x-rays hit the recording media which may be either film or a CCD (Charge Couple Device) or CMOS (Complementary Metal Oxide Semiconductor) chip used for digital recording. Solutions Discovered And Implemented By NIC
NIC has successfully created a novel scintillator based on a micro-channel plate containing between 2-3 million channels per square inch. Each channel contains NIC's proprietary blend of highly efficient phosphors. This scintillator, the creation and design of which is protected by several patents, collimates impacting x-rays and also converts/absorbs them so that the highly sensitive CCD or CMOS is not damaged. A high resolution digital image is obtained by integrating the scintillator with the CCD or CMOS. NIC technology improves x-ray imaging by improving the high-resolution imaging efficiency. High-resolution efficiency is particularly important in the mammography and dental x-ray imaging markets. For a given x-ray exposure, NIC technology uncovers finer features and structures. NIC enabled x-ray systems extract more diagnostic information, leading to more accurate, cost effective, and potentially life-saving diagnosis. See digitaly recorded images below. 
The resolution of an image is measured by the number of distinct, adjacent black and white lines within one millimeter ( line-pairs) which the human eye can resolve when looking at an enlargement of the image. The picture above shows a comparison of resolution-performance of MR (Kodak Min-R screen), CsI (Cesium Iodide process used by GE/Siemens) and NIC scintillator technology. Bar-test patterns of an x-ray imaging phantom at 10,15,and 20 lp/mm show the superior resolution of the NIC scintillator. NIC will continue to improve its image quality beyond the level shown above. The other two processes have certain inherent scientific limitations. 
A comparison of CT-Scan of a mouse The blood vessels of a pig's
showing the detailed view of spinal canal area.
The NIC-CT image was taken
at 1/250 dosage of the Conventional CT NIC's First Digital X-ray Imaging Product
NIC's first commercial product is a scintillator to be used as a part of a dental imaging sensor manufactured by other vendors. This product has been tested by the leading manufacturers of dental imaging sensors in Europe and Japan. They found that NIC's dental scintillator helps them to achieve superior image resolution. It is anticipated that sales of the scintillator to foreign manufacturers will commence in fall 2002. NIC's First Comercial Product - Digital Dental Imaging Sensor NIC is also working towards integrating its scintillator with CCD/CMOS to create a complete digital dental imaging sensor. This product will be ready for the market in the latter part of 2003. This unit can be used in conjunction with existing film imaging equipment already in place. Based upon current retail price of sensors sold by other manufacturers, it is anticipated that this unit will retail between $6000 to $7000. There are approximately 160,000 dentists in the United Sates and 700,000 dentists worldwide. About 8% of dentists in USA use a digital imaging system even though the saving of the dentist's time as well as the convenience of such a system is obvious. The reason is poor digital image quality. Dentists overseas have barely begun to use digital imaging systems in significant numbers. Endodontists in particular favor digital imaging because of their need for real time images. NIC selected the dental market for its initial medical market entry because of:
(a) ease of FDA approval (150 days);
(b) no major manufacturer sells into this market (12 small players with non-proprietary scintillators compete on price in a fragmented market having less than 10% digital penetration);
(c) image quality of existing digital dental systems is still inferior to film;
(d) NIC's images are superior by a factor of 100% in terms of resolution/contrast and, importantly, reduced x-ray exposure (about 20% of film); and
(e) dental practices are entrepreneurial in nature and will be sensitive to superior image quality, convenience of real time, digital storage and transmission, avoiding development of film, savings in time; Other Digital X-ray Imaging Products
The basic technology platform created by NIC can be rapidly deployed to create products for other medical imaging modalities such as:
Mammography : NIC's next area of concentration will be in mammography imaging. This medical application is especially suited for NIC's high resolution capabilities. It is also anticipated that NIC's end user cost of a superior digital mammography sensor will be approximately one-third of that of the competition.
Osteoporosis : The digital modality is also well suited for the osteoporosis ( bone density mapping ) market.
Micro CT-SCAN. High resolution micro CT-SCAN equipment will be of great help to take images of laboratory mice which are used for testing drugs in development. At present, mice have to be killed and frozen sections analyzed under a microscope to track the impact of the drug. The capability to image cellular structures without killing the mouse will reduce the time required for drug development by approximately 40%
Cardiac Imaging :The real-time high-resolution and high-contrast x-ray images would help the cardiologists to perform catheterization and in particular the manipulation of catheter and placement of stents. Next generation cardiac imaging systems are expected to observe plaque formation.
Oncology Imaging : The high-contrast and high-resolution should help us to locate the boundaries of cancer growth for radiation therapy treatment. These products will be introduced over the next five years. NIC's Long Term Vision: Digital Desktop Medical Imaging
NIC long term vision in the area of medical imaging is to create affordably priced desktop digital x-ray imaging systems which depend on very low x-ray dosage and hence can be placed in the average physician's office. This revolution in medical imaging will greatly expand the worldwide market for such products. Industrial Imaging
The technology platform developed by NIC for medical imaging can also be used in various industrial imaging applications such as electronic chip inspection, high sensitivity security imaging, fault inspection in critical castings etc. As at present, NIC has no plan to address this market in view of its initial concentration on the medical market. NIC will nevertheless be alert to exploit licensing and/or strategic partnering opportunities as they arise. NANOCRYSTAL LIGHTIN Commercialize products based upon the 'Quantum Confined Atom' (QCA) for all applications in the field of lighting. In order to have efficient lamps, nanophosphors that will generate efficient white light under UV excitation. Discovery has unequivocally demonstrated that in QCA based nanomaterials, the efficiency of the light emanating from a single caged atom (ion) is the highest when the particle size is less than 5nm. As the size decreases from 10 nm to 2 nm, the light from the caged atom increases non-linearly. These nanophosphors of size range 2 to 5 nm, when properly incorporated in a clear polymer provides efficient, transparent and high-index nano-composite materials that down-convert UV-light emitting diodes to white solid state lamps. The engineering of an atom (ion) in the nano-regime has allowed us to significantly change the paradigm of designing new phosphors and lenses for all lamps. The control of refractive index with use of QCA based nanophosphors is also expected to impact all optical, transparent materials where high refractive index is desirable, such as optometry, specialty glass e Display Devices
Semiconductor nanocrystals could provide superior brightness and color for: ♦ LED Lights (see picture)
♦ LED Displays for Computers, Cameras, Phones, and Much Much More! Energy Generation
Nanocrystals could be the next generation of photovoltaics. Two major problems currently plague solar cells, low specific power efficiency and high cost. Nano-engineered solar cells could solve these two issues simultaneously. Other Bio-tags for Gene Identification and Medical Imaging
Protein Analysis
Flat-slim Displays
Lasers and Optical Components
Magneto-optical Memories
Self-organized Smart Materials Related research 1. "Efficient, Stable, Small, and Water-Soluble Doped ZnSe Nanocrystal Emitters as Non-Cadmium Biomedical Labels." N. Pradhan, D. Battaglia, Y. Liu, X. Peng, Nano Lett., 2007, vol 7, no 2, p 312. 2. "An Alternative of CdSe Nanocrystal Emitters: Pure and Tunable Impurity Emissions in ZnSe Nanocrystals." N. Pradhan, D. Goorskey, J. Thessing, X. Peng, J. Am. Chem. Soc., 2005, vol 127, p 17586. 3. "Super-Stable, High-Quality Fe3O4 Dendron-Nanocrystals Dispersible in Both Organic and Aqueous Solutions." M. Kim, Y. Chen, Y. Liu, X. Peng, Adv. Mater., 2005, vol 7, p 1429. 4. "Size-Dependent Dissociation pH of Thiolate Ligands from Cadmium Chalcogenide Nanocrystals." J. Aldana, N. Lavelle, Y. Wang, X. Peng, J. Am. Chem. Soc., 2005, vol 127, p 2496. 5. "Photocatalytic Activity of Gold Nanocrystals and Its Role in Determining the Stability of Surface Thiol Monolayers." J. J. Li, X. Peng, J. Nano. Scie., 2004, vol 4, p 265. 6. "Size- and Shape-Controlled Magnetic (Cr, Mn, Fe, Co, Ni) Oxide Nanocrystals via a Simple and General Approach." N. R. Jana, Y. Chen, X. Peng, Chem. Mater., 2004, vol 16, p 3931. 7. "Single-Phase and Gram-Scale Synthesis of Au and Other Noble Metal Nanocrystals." N. R. Jana, X. Peng, J. Am. Chem. Soc., 2003, vol 125, p 14280. 8. "Colloidal Two-Dimensional Systems, CdSe Quantum Shells and Wells." D. Battaglia, J. J. Li, Y. Wang, X. Peng, Angew. Chem. Int. Ed., 2003, vol 43, p 5035. 9. "Large-Scale Synthesis of Nearly Monodisperse CdSe/CdS Core/Shell Nanocrystals Using Air-Stable Reagents via Successive Ion Layer Adsorption and Reaction." J. Li, Y. A. Wang, W. Guo, J. C. Keay, T. D. Mishima, M. B. Johnson, X. Peng., J. Am. Chem. Soc., 2003, vol 125, p 12567. 10. "Green Chemical Approaches toward High Quality Semiconductor Nanocrystals." X. Peng, Chem. Eu. J., 2002, vol 8, p 334 (invited concept article). 11. "Formation and Stability of Size-, Shape-, and Structure-Controlled CdTe Nanocrystals: Ligand Effects on Monomers and Nanocrystals." W. W. Yu, Y. A. Wang, X. Peng, Chem. Mater., 2003, p 4300. 12. "Nanocrystal in dendron-box: a versatile solution to the chemical, photochemical, and thermal instability of colloidal nanocrystals." Comptes Rendus Chimie, 2003, p 989. (invited) 13. "Mechanisms of Shape Control and Shape Evolution of Colloidal Nanocrystals." X. Peng, Adv. Mater., 2003, vol 15, p 459. (invited) 14. "Experimental Determination of the Extinction Coefficient of CdTe, CdSe, and CdS Nanocrystal." W. Yu, L. Qu, W. Guo, X. Peng, Chem. Mater., 2003, vol 15, p 2854. 15. "Conjugation Chemistry and Bio-Applications of Semiconductor Box-Nanocrystals Prepared via Dendrimer-Bridging." W. Guo, J. Li, Y. A. Wang, X. Peng, Chem. Mater., 2003, vol 15, p 3125. 16. "Formation of High Quality CdS and Other II-VI Semiconductor Nanocrystals in Non-Coordinating Solvent, Tunable Reactivity of Monomers." Yu W., Peng X., Angew. Chem. Int. Ed., 2002, vol 41, p 2368. (Announced as a "hot paper" by the journal) 17. "Nearly Monodisperse and Shape-Controlled CdSe Nanocrystals via Alternative Routes: Nucleation and Growth." Z. Peng, X. Peng, J. Am. Chem. Soc., 2002, vol 124, p 3343. 18. "Stabilization of Inorganic Nanocrystals by Organic Dendrons." Y.A. Wang, J.J. Li, H. Chen, X. Peng, J. Am. Chem. Soc., 2002, vol 124, 2293-2298. 19. "Luminescent CdSe/CdS Core/Shell Nanocrystals in Dendron Boxes: Superior Chemical, Photochemical and Thermal Stability." W. Guo, J.J. Li, Y.J. Wang, X. Peng,J. Am. Chem. Soc., 2003, vol 125 3901-3909. 20. "Formation of High-Quality CdTe, CdSe, and CdS Nanocrystals Using CdO as Precursor." Peng Z. A., Peng X., J. Am. Chem. Soc., 2001, vol 123, p 183. (highlighted in C&En News) 21. "Photochemical Instability of CdSe Nanocrystals Coated by Hydrophilic Thiols." J. Aldana, Y.A. Wang, X. Peng, J. Am. Chem. Soc., 2001, 123, p 8844. 22. "Alternative Routes toward High Quality CdSe Nanocrystals." L. Qu, Z.A. Peng, X. Peng, Nano Lett., 2001, vol 1, p 333.
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