Science Current Events | Science News | Brightsurf.com
 

Tiny crystals promise big benefits for solar technologies

January 05, 2006

Los Alamos National Laboratory scientists have discovered that a phenomenon called carrier multiplication, in which semiconductor nanocrystals respond to photons by producing multiple electrons, is applicable to a broader array of materials that previously thought. The discovery increases the potential for the use of nanoscrystals as solar cell materials to produce higher electrical outputs than current solar cells.

In papers published recently in the journals Nature Physics and Applied Physics Letters, the scientists demonstrate that carrier multiplication is not unique to lead selenide nanocrystals, but also occurs with very high efficiency in nanocrystals of other compositions, such as cadmium selenide. In addition, these new results shed light on the mechanism for carrier multiplication, which likely occurs via the instantaneous photoexcitation of multiple electrons. Such a process has never been observed in macroscopic materials and it explicitly relies on the unique physics of the nanoscale size regime.

According to Richard Schaller, a Los Alamos scientist on the team, "Our research of carrier multiplication in previous years was really focused on analyzing the response of lead selenide nanocrystals to very short laser pulses. We discovered that the absorption of a single photon could produce two or even three excited electrons. We knew, somewhat instinctively, that carrier multiplication was probably not confined to lead selenide, but we needed to pursue the question."

Lead project scientist Victor Klimov explains, "Carrier multiplication actually relies upon very strong interactions between electrons squeezed within the tiny volume of a nanoscale semiconductor particle. That is why it is the particle size, not its composition that mostly determines the efficiency of the effect. In nanosize crystals, strong electron-electron interactions make a high-energy electron unstable. This electron only exists in its so-called 'virtual state' for an instant before rapidly transforming into a more stable state comprising two or more electrons."

The Los Alamos findings point toward practical photovoltaic technologies that may utilize such traditional solar cell materials as cadmium telluride, which is very similar to cadmium selenide. Other interesting opportunities may also be associated with the use of carrier multiplication in solar-fuel technologies and specifically, the production of hydrogen by photo-catalytic water splitting. The latter process requires four electrons per water molecule and its efficiency can be dramatically enhanced if these multiple electrons can be produced via a single-photon absorption event.

DOE/Los Alamos National Laboratory


Related Solar Technologies Current Events and Solar Technologies News Articles


'Hydricity' concept uses solar energy to produce power round-the-clock
Researchers are proposing a new "hydricity" concept aimed at creating a sustainable economy by not only generating electricity with solar energy but also producing and storing hydrogen from superheated water for round-the-clock power production.

New approaches for hybrid solar cells
Using a new procedure researchers at the Technical University of Munich (TUM) and the Ludwig Maximillians University of Munich (LMU) can now produce extremely thin and robust, yet highly porous semiconductor layers. A very promising material - for small, light-weight, flexible solar cells, for example, or electrodes improving the performance of rechargeable batteries.

Building the electron superhighway
TV screens that roll up. Roofing tiles that double as solar panels. Sun-powered cell phone chargers woven into the fabric of backpacks.

Solar could meet California energy demand 3 to 5 times over
In the face of global climate change, increasing the use of renewable energy resources is one of the most urgent challenges facing the world.

A ray of sunshine for bioenergy
Even at historically low natural gas prices, bioenergy may not be out of the running -- it just may need a little help from the sun. A new study from researchers at the University of Minnesota examining the financial viability of solar-heated biomass gasification technologies that produce a natural gas substitute product concludes that combining these renewable resources can make economic sense.

Calculating the future of solar-fuel refineries
A team of University of Wisconsin-Madison engineers has developed a new tool to help plot the future of solar fuels.

NTU invents smart window that tints and powers itself
Nanyang Technological University (NTU) scientists have developed a smart window which can darken or brighten without the need for an external power source.

New technique offers spray-on solar power
Pretty soon, powering your tablet could be as simple as wrapping it in cling wrap.

Wind energy cuts the electricity bill
The promoting of renewable energy is at the heart of the current debate on energy policy.

Net energy analysis should become a standard policy tool, Stanford scientists say
Policymakers should conduct "net energy analyses" when evaluating the long-term sustainability of energy technologies, according to new Stanford University research.
More Solar Technologies Current Events and Solar Technologies News Articles

Solar Energy: The Physics and Engineering of Photovoltaic Conversion, Technologies and Systems

Solar Energy: The Physics and Engineering of Photovoltaic Conversion, Technologies and Systems
by Olindo Isabella (Author), Klaus Jäger (Author), Arno Smets (Author), René van Swaaij (Author), Miro Zeman (Author)


This comprehensive textbook takes you through everything you need to know about solar energy from the physics of photovoltaic (PV) cells through to the design of PV systems for real-life applications. Solar Energy is an invaluable reference for researchers, industrial engineers and designers working in solar energy generation. The book is also ideal for university and third-level physics or engineering courses on solar photovoltaics, with exercises to check students’ understanding and reinforce learning. It is the perfect companion to the Massive Open Online Course (MOOC) on Solar Energy (DelftX, ET.3034TU) presented by co-author Arno Smets. The course is available in English on the nonprofit open source edX.org platform, and in Arabic on edraak.org. Over 100,000 students have already...

DIY Solar Heater: 20 Lessons How To Build and Use a Solar Air Heater: (Energy Independence, Lower Bills & Off Grid Living) (Power Generation) (Volume 1)

DIY Solar Heater: 20 Lessons How To Build and Use a Solar Air Heater: (Energy Independence, Lower Bills & Off Grid Living) (Power Generation) (Volume 1)
by Chad Babcock (Author)


Getting Your FREE Bonus Download this book, read it to the end and see "BONUS: Your FREE Gift" chapter after the conclusion. DIY Solar Heater: (FREE Bonus Included) 20 Lessons How To Build and Use a Solar Air Heater Needless to say, when the winter weather arrives; it gets cold! Some of you right now may be struggling to stay warm and it takes a toll on you, not only physically, but financially as well. But don’t worry friends, because there is a DIY solution for your winter heating needs right around the corner. Because using the information gathered right here in this book you can learn how you can easily and efficiently heat your home all year long with your very own DIY solar heater. Instead of having your utility bills dictate how you spend all of your hard earned money, you can...

Solar Energy: Technologies and Project Delivery for Buildings

Solar Energy: Technologies and Project Delivery for Buildings
by Andy Walker (Author)


Paperback International Edition ... Same contents as in the US edition at Low Cost !!

Photovoltaic Design and Installation For Dummies

Photovoltaic Design and Installation For Dummies
by Ryan Mayfield (Author)


The fun and easy way to get a grip on photovoltaic design and installation Designing and installing solar panel systems is a trend that continues to grow. With 'green collar' jobs on the rise and homeowners looking for earth-friendly ways to stretch their dollars and lesson their carbon imprint, understanding photovoltaic design and installation is on the rise. Photovoltaic Design & Installation For Dummies gives you a comprehensive overview of the history, physics, design, installation, and operation of home-scale solar-panel systems. You'll also get an introduction to the foundational mathematic and electrical concepts you need to understand and work with photovoltaic systems. Covers all aspects of home-scale solar-power systems Viable resource for professionals, students, and...

Solar Power Demystified: The Beginners Guide To Solar Power, Energy Independence And Lower Bills

Solar Power Demystified: The Beginners Guide To Solar Power, Energy Independence And Lower Bills
by Digital Publishing Ltd


New Internet Linked Edition to Free Solar Resources and Free Solar Calculators!The book 'Solar Power Demystified: The Beginners Guide To Solar Power, Energy Independence And Lower Bills' introduces you to the world of solar electric panels and systems.

It reveals you the reasons why photovoltaic solar panels are continuing to gain worldwide popularity and are becoming more important as a source of renewable energy.

You can see the question "To go or not to go solar?" discussed in its practical aspects.
Furthermore you are advised what kind of solar electric system you need and how to evaluate whether your home is 'solar-ready' or not

You are also introduced to the basics of photovoltaics and to the main types of solar electric systems and their...

Real Goods Solar Living Source Book--Special 30th Anniversary Edition: Your Complete Guide to Renewable Energy Technologies and Sustainable Living

Real Goods Solar Living Source Book--Special 30th Anniversary Edition: Your Complete Guide to Renewable Energy Technologies and Sustainable Living
by John Schaeffer (Author)


Concerns over dwindling resources and environmental degradation are driving many to seek alternatives to our wasteful, polluting lifestyle. Clean technologies such as solar power, wind power, and biodiesel fuel are soaring in popularity. Real Goods Solar Living Source Book—Special 30th Anniversary Edition is the ultimate guide to renewable energy, sustainable living, green building, homesteading, off-the-grid living, and alternative transportation, written by experts with decades of experience and a passion for sharing their knowledge. This fully updated edition includes brand-new sections on Peak Oil, climate change, relocalization, natural burial, biodynamics, and permaculture. It also boasts the latest product listings and completely rewritten and expanded chapters on: Land and...

Solar Power Technologies Explained Simply: Energy Technologies Explained Simply (Volume 5)

Solar Power Technologies Explained Simply: Energy Technologies Explained Simply (Volume 5)
by Mark Fennell (Author)


Solar Power Technologies Explained Simply is a practical and easy-to-read resource for anyone interested in Solar Power. This book discusses everything you need to know about solar power systems and solar cell technologies. There are three major parts to this book: 1. Overview of Solar Power Technologies 2. Practical Considerations when Installing Solar Cells 3. Advanced Solar Cell Technologies. The first part provides an overview of solar cell technologies. Topics include the basic process of solar cells, processes which limit the efficiency of solar cells, and key terminology. This part of the book also provides an overview of practical issues to consider when using solar power. The second part of the book discusses all of the most important practical considerations when...

Solar Electricity Handbook - 2015 Edition: A simple, practical guide to solar energy - designing and installing solar PV systems.

Solar Electricity Handbook - 2015 Edition: A simple, practical guide to solar energy - designing and installing solar PV systems.
by Michael Boxwell (Author)


The Solar Electricity Handbook - 2015 Edition, is a simple, practical guide to using electric solar panels and designing and installing photovoltaic PV systems. Now in its ninth edition, the book assumes no previous knowledge of solar electric systems. The book explains how solar panels work and how they can be used. It explains the advantages of solar energy and the drawbacks that you need to take into account when designing a solar power system. As well as explaining the underlying principles, it provides a step-by-step guide so that you can successfully design and install a photovoltaic solar system from scratch. Unlike many guides, The Solar Electricity Handbook explains the principles behind the technology, allowing the reader to design solar energy systems with confidence. The book...

Solar Weapon

Solar Weapon
by Clearwater Valley Press, LLC


A secret group of elite people has broken away from our civilization and now demand the entire world bow to their power.
IF every nation on Earth doesn't surrender total control to that elitist group, a Coronal Mass Ejection will be triggered on the sun, creating an Extinction Level Event that will incinerate the surface of the planet.
FBI agent Jake Hunter and NSA agent Honika Badger scramble through a maze of clues and evidence, desperately trying to discover who is behind this threat, and figure out how they can be stopped, as the resolve of the elite group is terrifyingly demonstrated.


Solar Electricity Handbook: 2017 Edition: A simple, practical guide to solar energy ? designing and installing solar photovoltaic systems.

Solar Electricity Handbook: 2017 Edition: A simple, practical guide to solar energy ? designing and installing solar photovoltaic systems.
by Mr Michael Boxwell (Author)


Solar Energy is a wonderful concept. Take free energy from the sun and use it to power electrical equipment. No ongoing electricity bills, no reliance on an electricity socket. ‘Free’ electricity that does not harm the planet. Of course, the reality is more complicated than that, yet generating electricity from sunlight alone is a powerful resource, with applications and benefits throughout the world. But how does it work? What is it suitable for? How much does it cost? How do I install it? This best-selling, internet linked book answers all these questions and shows you how to use the power of the sun to generate electricity yourself. Now in its eleventh edition, this book assumes no previous knowledge. It explains the advantages of solar energy and the drawbacks you need to take...

© 2017 BrightSurf.com