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20120406183244644

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Mantosh Gpt
Mantosh Gpt

Nanoparticles range from 1-100nm in size and may exhibit size-dependent properties different from bulk materials. Mesoporous silica nanoparticles have been created with diameters of 20nm, 45nm, and 80nm using TEM and SEM imaging. Quantum dots are semiconductor nanoparticles less than 10nm that show quantized energy levels resulting in size-dependent colors from their light emission. Potential applications of nanoparticles and quantum dots include biomedical imaging, solar cells, LEDs and other electronic and optical devices.

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5.Nanoparticles & quantum dots ? fine particles: cover a range 100 - 2500 nm. ? ultrafine particles, 1 and 100 nm. ? Similar to ultrafine particles, nanoparticles 1- 100nm. ? Nanoparticles may or may not exhibit size-related properties that differ significantly from those observed in fine particles or bulk materials. ? Nanoparticle research is currently an area of intense scientific interest due to a wide variety of potential applications in biomedical, optical and electronic fields.
silica nanoparticles TEM (a, b, and c) images of prepared mesoporous silica nanoparticles with mean outer diameter: (a) 20nm, (b) 45nm, and (c) 80nm. SEM (d) image corresponding to (b). The insets are a high magnification of mesoporous silica particle.
Nanostars of vanadium(IV) oxide At the small end of the size range, nano-particles are often referred to as clusters( ´Ø£¬¼¯Èº ). Spheres( Çò ), rods( °ô ), fibers( ¹âÏË ), and cups are just a few of the shapes that have been grown.
Long history of the Nanoparticle ?Although nano-particles are generally considered an invention of modern science, they actually have a very long history. Nano-particles were used by artisans as far back as the 9th century in Mesopotamia for generating a glittering effect on the surface of pots. Deep Dish from Spain, after 1475[1] Tin- glazed earthenware with lustred decoration, Victoria and Albert Museum, London Earthenware cup with lustre decoration, 10th century, from Susa, Iran
Application of Nanoparticles ?nanoparticles of usually yellow gold and gray silicon are red in color; ?absorption of solar radiation in photovoltaic cells is much higher in materials composed of nanoparticles than it is in thin films of continuous sheets of material ¨C the smaller the particles, the greater the solar absorption. ?the presence of titanium dioxide nanoparticles imparts what we call the self-cleaning effect, and the size being nanorange, the particles can not be observed. Zinc oxide particles have been found to have superior UV blocking properties compared to its bulk substitute. ?Clay nanoparticles when incorporated into polymer matrices increase reinforcement, leading to stronger plastics, verifiable by a higher glass transition temperature and other mechanical property tests. These nanoparticles are hard, and impart their properties to the polymer (plastic).
Application of Nanoparticles ?Nanoparticles have also been attached to textile fibers in order to create smart and functional clothing. ?Metal, dielectric, and semiconductor nanoparticles have been formed, as well as hybrid structures (e.g., core-shell nanoparticles). Nanoparticles made of semiconducting material may also be labeled quantum dots if they are small enough (typically sub 10 nm) that quantization of electronic energy levels occurs. Such nanoscale particles are used in biomedical applications as drug carriers or imaging agents.
What are Quantum Dots? ? Quantum dots are semiconductor nanocrystals that are so small they are considered dimensionless. ? Quantum dots range from 2-10 nanometers (10-50 atoms)in diameter.
Quantum dot What is quantum dot? is a semiconductor whose excitons are confined in all three spatial dimensions. Consequently, such materials have electronic properties intermediate between those of bulk semiconductors and those of discrete molecules Researching fields: have studied quantum dots in transistors , solar cells, LEDs, and diode lasers. Colloidal quantum dots irradiated with a UV light. Different sized quantum dots emit They have also investigated quantum different color light due to quantum dots as agents for medical imaging and confinement. hope to use them as qubits WHY? HOW?
Several important quantum confinement structures, (a)quantum well, (b) quantum wire, and (c) quantum dot.
Quantum Dot , Quantum Wires and Quantum Well Besides confinement in all three dimensions i.e. Quantum Dot - other quantum confined semiconductors include: quantum wires, which confine electrons or holes in two spatial dimensions and allow free propagation in the third. quantum wells, which confine electrons or holes in one dimension and allow free propagation in two dimensions.
20120406183244644
Colorific Properties ? The height,and energy difference,between energy levels increases as the size of the quantum dot decreases. ? Smaller Dot=Higher Energy=Smaller Wavelength=Blue Color
Color & Quantum Dots
Characteristics of Quantum Dot ?Generally, the smaller the size of the crystal, the larger the band gap, the greater the difference in energy between the highest valence band and the lowest conduction band becomes, therefore more energy is needed to excite the dot, and concurrently, more energy is released when the crystal returns to its resting state. ?this equates to higher frequencies of light emitted after excitation of the dot as the crystal size grows smaller, resulting in a color shift from red to blue in the light emitted. ?In addition to such tuning, a main advantage with quantum dots is that, because of the high level of control possible over the size of the crystals produced, it is possible to have very precise control over the conductive properties of the material
Optical Properties ?quantum dots of the same material, but with different sizes, can emit light of different colors. The physical reason is the quantum confinement effect. ?The larger the dot, the redder (lower energy) its fluorescence spectrum. Conversely, smaller dots emit bluer (higher energy) light. The coloration is directly related to the energy levels of the quantum dot. ? As with any crystalline semiconductor, Researchers at Los Alamos National Laboratory a quantum dot's electronic wave functions have developed a wireless device that efficiently produces visible light, through energy transfer extend over the crystal lattice. Similar to a from thin layers of quantum wells to crystals molecule, a quantum dot has both a above the layers. quantized energy spectrum and a quantized density of electronic states near the edge of the band gap.
Applications of Quantum Dots
Applications Quantum dots are particularly significant for optical applications due to their high extinction co-efficient , single-electron transistor, implementations of qubits for quantum information process Computing Biology Photovoltaic device Light emitting device
20120406183244644
20120406183244644
20120406183244644
Conclusions ? Quantum Dots are a new and innovative perspective on the traditional semiconductor. ? Quantum Dots can be synthesized to be essentially any size,and therefore,produce essentially any wavelength of light. ? There are many possible applications of Quantum Dots in many different areas of industry/science. ? The future looks bright and exciting on all the possible applications of Quantum Dots.

More Related Content

20120406183244644

  • 1. 5.Nanoparticles & quantum dots ? fine particles: cover a range 100 - 2500 nm. ? ultrafine particles, 1 and 100 nm. ? Similar to ultrafine particles, nanoparticles 1- 100nm. ? Nanoparticles may or may not exhibit size-related properties that differ significantly from those observed in fine particles or bulk materials. ? Nanoparticle research is currently an area of intense scientific interest due to a wide variety of potential applications in biomedical, optical and electronic fields.
  • 2. silica nanoparticles TEM (a, b, and c) images of prepared mesoporous silica nanoparticles with mean outer diameter: (a) 20nm, (b) 45nm, and (c) 80nm. SEM (d) image corresponding to (b). The insets are a high magnification of mesoporous silica particle.
  • 3. Nanostars of vanadium(IV) oxide At the small end of the size range, nano-particles are often referred to as clusters( ´Ø£¬¼¯Èº ). Spheres( Çò ), rods( °ô ), fibers( ¹âÏË ), and cups are just a few of the shapes that have been grown.
  • 4. Long history of the Nanoparticle ?Although nano-particles are generally considered an invention of modern science, they actually have a very long history. Nano-particles were used by artisans as far back as the 9th century in Mesopotamia for generating a glittering effect on the surface of pots. Deep Dish from Spain, after 1475[1] Tin- glazed earthenware with lustred decoration, Victoria and Albert Museum, London Earthenware cup with lustre decoration, 10th century, from Susa, Iran
  • 5. Application of Nanoparticles ?nanoparticles of usually yellow gold and gray silicon are red in color; ?absorption of solar radiation in photovoltaic cells is much higher in materials composed of nanoparticles than it is in thin films of continuous sheets of material ¨C the smaller the particles, the greater the solar absorption. ?the presence of titanium dioxide nanoparticles imparts what we call the self-cleaning effect, and the size being nanorange, the particles can not be observed. Zinc oxide particles have been found to have superior UV blocking properties compared to its bulk substitute. ?Clay nanoparticles when incorporated into polymer matrices increase reinforcement, leading to stronger plastics, verifiable by a higher glass transition temperature and other mechanical property tests. These nanoparticles are hard, and impart their properties to the polymer (plastic).
  • 6. Application of Nanoparticles ?Nanoparticles have also been attached to textile fibers in order to create smart and functional clothing. ?Metal, dielectric, and semiconductor nanoparticles have been formed, as well as hybrid structures (e.g., core-shell nanoparticles). Nanoparticles made of semiconducting material may also be labeled quantum dots if they are small enough (typically sub 10 nm) that quantization of electronic energy levels occurs. Such nanoscale particles are used in biomedical applications as drug carriers or imaging agents.
  • 7. What are Quantum Dots? ? Quantum dots are semiconductor nanocrystals that are so small they are considered dimensionless. ? Quantum dots range from 2-10 nanometers (10-50 atoms)in diameter.
  • 8. Quantum dot What is quantum dot? is a semiconductor whose excitons are confined in all three spatial dimensions. Consequently, such materials have electronic properties intermediate between those of bulk semiconductors and those of discrete molecules Researching fields: have studied quantum dots in transistors , solar cells, LEDs, and diode lasers. Colloidal quantum dots irradiated with a UV light. Different sized quantum dots emit They have also investigated quantum different color light due to quantum dots as agents for medical imaging and confinement. hope to use them as qubits WHY? HOW?
  • 9. Several important quantum confinement structures, (a)quantum well, (b) quantum wire, and (c) quantum dot.
  • 10. Quantum Dot , Quantum Wires and Quantum Well Besides confinement in all three dimensions i.e. Quantum Dot - other quantum confined semiconductors include: quantum wires, which confine electrons or holes in two spatial dimensions and allow free propagation in the third. quantum wells, which confine electrons or holes in one dimension and allow free propagation in two dimensions.
  • 12. Colorific Properties ? The height,and energy difference,between energy levels increases as the size of the quantum dot decreases. ? Smaller Dot=Higher Energy=Smaller Wavelength=Blue Color
  • 14. Characteristics of Quantum Dot ?Generally, the smaller the size of the crystal, the larger the band gap, the greater the difference in energy between the highest valence band and the lowest conduction band becomes, therefore more energy is needed to excite the dot, and concurrently, more energy is released when the crystal returns to its resting state. ?this equates to higher frequencies of light emitted after excitation of the dot as the crystal size grows smaller, resulting in a color shift from red to blue in the light emitted. ?In addition to such tuning, a main advantage with quantum dots is that, because of the high level of control possible over the size of the crystals produced, it is possible to have very precise control over the conductive properties of the material
  • 15. Optical Properties ?quantum dots of the same material, but with different sizes, can emit light of different colors. The physical reason is the quantum confinement effect. ?The larger the dot, the redder (lower energy) its fluorescence spectrum. Conversely, smaller dots emit bluer (higher energy) light. The coloration is directly related to the energy levels of the quantum dot. ? As with any crystalline semiconductor, Researchers at Los Alamos National Laboratory a quantum dot's electronic wave functions have developed a wireless device that efficiently produces visible light, through energy transfer extend over the crystal lattice. Similar to a from thin layers of quantum wells to crystals molecule, a quantum dot has both a above the layers. quantized energy spectrum and a quantized density of electronic states near the edge of the band gap.
  • 17. Applications Quantum dots are particularly significant for optical applications due to their high extinction co-efficient , single-electron transistor, implementations of qubits for quantum information process Computing Biology Photovoltaic device Light emitting device
  • 21. Conclusions ? Quantum Dots are a new and innovative perspective on the traditional semiconductor. ? Quantum Dots can be synthesized to be essentially any size,and therefore,produce essentially any wavelength of light. ? There are many possible applications of Quantum Dots in many different areas of industry/science. ? The future looks bright and exciting on all the possible applications of Quantum Dots.

Editor's Notes

  • #17: Future Applications of Quantum Dots White LED's-Replace Incandescent Light bulbs with red,green and blue QD's to get white light. Active LED's-can get any color needed virtually pain free;since QD's are so small,they can be inserted into basically anything. Life Sciences-can be used in place of traditional organic dyes;last longer and can be tuned more specifically than organic dyes.