 |
|
Silicon nanoparticles enhance performance of solar cells
August 21, 2007CHAMPAIGN, Ill. - Placing a film of silicon nanoparticles onto a silicon solar cell can boost power, reduce heat and prolong the cell's life, researchers now report.
"Integrating a high-quality film of silicon nanoparticles 1 nanometer in size directly onto silicon solar cells improves power performance by 60 percent in the ultraviolet range of the spectrum," said Munir Nayfeh, a physicist at the University of Illinois and corresponding author of a paper accepted for publication in Applied Physics Letters.
A 10 percent improvement in the visible range of the spectrum can be achieved by using nanoparticles 2.85 nanometers in size, said Nayfeh, who also is a researcher at the university's Beckman Institute.
In conventional solar cells, ultraviolet light is either filtered out or absorbed by the silicon and converted into potentially damaging heat, not electricity. In previous work, however, Nayfeh showed that ultraviolet light could efficiently couple to correctly sized nanoparticles and produce electricity. That work was reported in the August 2004 issue of the journal Photonics Technology Letters.
To make their improved solar cells, the researchers began by first converting bulk silicon into discrete, nano-sized particles using a patented process they developed. Depending on their size, the nanoparticles will fluoresce in distinct colors.
Nanoparticles of the desired size were then dispersed in isopropyl alcohol and dispensed onto the face of the solar cell. As the alcohol evaporated, a film of closely packed nanoparticles was left firmly fastened to the solar cell.
Solar cells coated with a film of 1 nanometer, blue luminescent particles showed a power enhancement of about 60 percent in the ultraviolet range of the spectrum, but less than 3 percent in the visible range, the researchers report.
Solar cells coated with 2.85 nanometer, red particles showed an enhancement of about 67 percent in the ultraviolet range, and about 10 percent in the visible.
The improved performance is a result of enhanced voltage rather than current, Nayfeh said. "Our results point to a significant role for charge transport across the film and rectification at the nanoparticle interface."
The process of coating solar cells with silicon nanoparticles could be easily incorporated into the manufacturing process with little additional cost, Nayfeh said.
University of Illinois at Urbana-Champaign
In conventional solar cells, ultraviolet light is either filtered out or absorbed by the silicon and converted into potentially damaging heat, not electricity. In previous work, however, Nayfeh showed that ultraviolet light could efficiently couple to correctly sized nanoparticles and produce electricity. That work was reported in the August 2004 issue of the journal Photonics Technology Letters.
To make their improved solar cells, the researchers began by first converting bulk silicon into discrete, nano-sized particles using a patented process they developed. Depending on their size, the nanoparticles will fluoresce in distinct colors.
Nanoparticles of the desired size were then dispersed in isopropyl alcohol and dispensed onto the face of the solar cell. As the alcohol evaporated, a film of closely packed nanoparticles was left firmly fastened to the solar cell.
Solar cells coated with a film of 1 nanometer, blue luminescent particles showed a power enhancement of about 60 percent in the ultraviolet range of the spectrum, but less than 3 percent in the visible range, the researchers report.
Solar cells coated with 2.85 nanometer, red particles showed an enhancement of about 67 percent in the ultraviolet range, and about 10 percent in the visible.
The improved performance is a result of enhanced voltage rather than current, Nayfeh said. "Our results point to a significant role for charge transport across the film and rectification at the nanoparticle interface."
The process of coating solar cells with silicon nanoparticles could be easily incorporated into the manufacturing process with little additional cost, Nayfeh said.
University of Illinois at Urbana-Champaign
Nanoparticles Current Events and Nanoparticles News RSSSweet -- sugared polymer a new weapon against allergies and asthma
Scientists at Johns Hopkins and their colleagues have developed sugar-coated polymer strands that selectively kill off cells involved in triggering aggressive allergy and asthma attacks.
Small nanoparticles bring big improvement to medical imaging
If you're watching the complex processes in a living cell, it is easy to miss something important-especially if you are watching changes that take a long time to unfold and require high-spatial-resolution imaging.
Nanotech in Space: Rensselaer Experiment To Weather the Trials of Orbit
Novel nanomaterials developed at Rensselaer Polytechnic Institute are scheduled to blast off into orbit on November 16 aboard Space Shuttle Atlantis.
Behavior modification could ease concerns about nanoparticles
In an advance that could help ease health and environmental concerns about the emerging nanotechnology industry, scientists are reporting development of technology for changing the behavior of nanoparticles in municipal sewage treatment plants - their main gateway into the environment.
Engineers image nanostructure of a solid acid catalyst and boost its catalytic activity
The catalytic processes that facilitate the production of many chemicals and fuels could become much more environmentally friendly thanks to a breakthrough achieved by researchers from Lehigh and Rice Universities.
Findings show nanomedicine promising for treating spinal cord injuries
Researchers at Purdue University have discovered a new approach for repairing damaged nerve fibers in spinal cord injuries using nano-spheres that could be injected into the blood shortly after an accident.
Chemists describe solar energy progress and challenges, including the 'artificial leaf'
Scientists are making progress toward development of an "artificial leaf" that mimics a real leaf's chemical magic with photosynthesis - but instead converts sunlight and water into a liquid fuel such as methanol for cars and trucks.
Magnetic nanoparticles to simultaneously diagnose, monitor and treat
Whether it's magnetic nanoparticles (mNPs) giving an army of 'therapeutically armed' white blood cells direction to invade a deadly tumour's territory, or the use of mNPs to target specific nerve channels and induce nerve-led behaviour (such as the life-dependant thumping of our hearts), mNPs have come a long way in the past decade.
An exquisite container
In campy old movies, Lucretia Borgia swans around emptying powder from her ring into wine glasses carelessly left unattended. The poison ring is usually a confection of gold filigree holding a cabochon or faceted gemstone that can be broken to empty the ring's contents. It is invariably enormous - so large it is rather odd nobody seems to notice it.
Hard Rain: Pitt-led Researchers Create Nano-Particle Coating to Prevent Freezing Rain Buildup on Roads, Power Lines
Preventing the havoc wrought when freezing rain collects on roads, power lines, and aircrafts could be only a few nanometers away.
More Nanoparticles Current Events and Nanoparticles News Articles
 |
Nanoparticles: From Theory to Application by Günter Schmid (Editor) An introduction to the science of nanoparticles, from fundamental principles to their use in novel applications. As a basis for understanding nanoparticle behavior, the book first outlines the principles of quantum size behavior, nanoparticles architecture, formation of semiconductor and metal nanoparticles. It then goes on to describe the chemical syntheses of nanoparticles with defined characteristics, their structural, electrical and magnetic properties, as well as current methods to monitor these properties. Among others, the following nanoparticle-based applications are discussed: * Single-electron devices * Ultra dense recording media * Bioelectronic devices and sensors * Labeling of proteins, nucleic acids and other biomaterials. ... |
 |
Nanoparticle Technology Handbook by Masuo Hosokawa (Editor), Kiyoshi Nogi (Editor), Makio Naito (Editor), Toyokazu Yokoyama (Editor) Nanoparticle technology, which handles the preparation, processing, application and characterisation of nanoparticles, is a new and revolutionary technology. It becomes the core of nanotechnology as an extension of the conventional Fine Particle / Powder Technology. Nanoparticle technology plays an important role in the implementation of nanotechnology in many engineering and industrial fields including electronic devices, advanced ceramics, new batteries, engineered catalysts, functional paint and ink, Drug Delivery System, biotechnology, etc.; and makes use of the unique properties of the nanoparticles which are completely different from those of the bulk materials. This new handbook is the first to explain complete aspects of nanoparticles with many application examples showing... |
 |
Nanoparticles Synthesis, Stabillization, passivation and Functionalization (Acs Symposium Series) by Ramanathan Nagarajan (Editor), T. Alan Hatton (Editor) Recent advances in the synthesis, stabilization, passivation and functionalization of a wide range of metal, metal oxide, semiconductor and other inorganic, polymer, organic, carbon and biological nanoparticles are reported in this book. Diverse shapes of nanoparticles are discussed here including spheres, cubes, nanorods, nanowires, nanotubes, nanocapsules, and nanopyramids. In the section on metals, one can find description of colloidal and wet chemical approaches to synthesize nanoparticles, methods to control number of functional groups and to attain aqueous dispersibility, impact of stabilizers on SERS activity, and ways to tune plasmon resonance via nanoparticle shapes. A time dependent density functional theory to evaluate adsorption properties of passivating ligands is also... |
 |
Nanoparticles: Building Blocks for Nanotechnology (Nanostructure Science and Technology) by Vincent Rotello (Author) The diverse structures and properties of nanoparticles make them useful tools for both fundamental studies and pragmatic applications in a range of disciplines. This volume is intended to explore this diversity. The first section covers on formation of nanoparticles, and assembly of these systems into structured systems. The second section focuses on both the fundamental physical properties of nanoparticles and pragmatic applications of these systems in the areas of device and materials fabrication. The book will approach the subject from a chemical standpoint, in contrast to most books which are oriented towards materials science or physics. It will also appeal to materials scientists and physicists who are becoming aware of the contributions that chemists can make here. |
|
International Journal of Nanoparticles by Inderscience Enterprises Ltd | |
 |
Metal Nanoparticles: Synthesis Characterization & Applications by Daniel L. Feldheim (Author) Offers the latest research on the synthesis, characterization, and applications of nanoparticle structural, optical, and electronic properties. |
 |
Nanoparticles and Catalysis by Didier Astruc (Editor) Written by international experts, this monograph combines two of the most important aspects of modern chemistry, presenting the latest knowledge on these environmental friendly applications. This result is a comprehensive overview of the application of nanoparticles in catalysis, focusing on synthesis and the most important reaction types, providing all the information needed by catalytic, organic and solid state chemists, as well as those working with or on organometallics, materials scientists, and chemists in industry. |
 |
Creme De Jour Tinted by Marie Veronique Organics zinc oxide sunscreen no harmful chemicals no nanoparticles |
 |
Synthesis, Functionalization and Surface Treatment of Nanoparticles by Marie-Isabelle Baraton (Author) Synthesis, functionalization and surface treatment of nanoparticles is an area of crucial importance in the emerging field of nanotechnology. Controlling the surface chemical composition and mastering its modification at the nanometer scale are critical issues for high-added value applications involving nanoparticles. The basic applications of surface functionalization range from altering the wetting or adhesion characteristics and improving the nanoparticles dispersion in matrices to enhancing the catalytic properties and ordering the interfacial region, and such. The creation of specific surface sites on nanoparticles for selective molecular attachment is considered a promising approach for their applications in nanofabrication, nanopatterning, selfassembly, nanosensors, bioprobes, drug... |
 |
60 Minutes - The Kanzius Machine (April 13, 2008) Airdate: 04/13/08 John Kanzius has no medical degree. In fact, he doesn't even have a college degree. But Kanzius does have terminal cancer, and that has motivated him to invent a radio-wave machine with the idea of treating cancer without the debilitating side effects of chemotherapy and radiation. Lesley Stahl tells this remarkable story of a leukemia patient so moved by the suffering of children with cancer that he has devoted himself to finding a cure. This product is manufactured on demand using DVD-R recordable media. Amazon.com's standard return policy will apply. |
| © 2009 BrightSurf.com |