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...

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...

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...

Solar PV Engineering and Installation: Preparation for the NABCEP PV Installation Professional Certification

Solar PV Engineering and Installation: Preparation for the NABCEP PV Installation Professional Certification
by Sean White (Author)


The NABCEP PV Installation Professional Exam is the gold standard certification exam for PV professionals and is famously difficult to pass. This book will provide test-taking strategy that can be used to most effectively study for and pass the exam. Code and theory is explained in the first half and will prove as useful background for the heart of the book which consists of practice exam questions and detailed explanations of the answers. It also contains essential strategy tools, short term memory tips and recommended reading which will be invaluable for anyone studying for the exam. The material in this book is not limited to those taking the exam as it will also be, more broadly, important for career progression and helping the reader to work safely with code compliant PV systems. ...

Off Grid Solar: A handbook for Photovoltaics  with Lead-Acid or Lithium-Ion batteries

Off Grid Solar: A handbook for Photovoltaics with Lead-Acid or Lithium-Ion batteries
by Joseph P O'Connor (Author)


Off Grid Solar is a pocket guide and quick reference for anyone looking to build an electrical energy system with the free sunshine available to us all. “The limitations to widespread solar are not centered on the cost, the efficiency, or the need for advancements in technology. The limitations are solely due to the lack of widespread knowledge on the subject.” With that philosophy at heart, solar and battery expert Joseph P. O’Connor draws from his years of experience to craft a how-to guide needed by everyone around the world. Founder of OCON Energy Consulting, O’Connor has conducted and taught the installation/maintenance of Off Grid solar projects to people and communities as far away as the central African rainforest and right in his own backyard of Oakland, California. For...

Solar Engineering of Thermal Processes

Solar Engineering of Thermal Processes
by John A. Duffie (Author), William A. Beckman (Author)


The updated fourth edition of the "bible" of solar energy theory and applications Over several editions, Solar Engineering of Thermal Processes has become a classic solar engineering text and reference. This revised Fourth Edition offers current coverage of solar energy theory, systems design, and applications in different market sectors along with an emphasis on solar system design and analysis using simulations to help readers translate theory into practice. An important resource for students of solar engineering, solar energy, and alternative energy as well as professionals working in the power and energy industry or related fields, Solar Engineering of Thermal Processes, Fourth Edition features: Increased coverage of leading-edge topics such as photovoltaics and the design of solar...

Solar Photovoltaic Basics: A Study Guide for the NABCEP Entry Level Exam

Solar Photovoltaic Basics: A Study Guide for the NABCEP Entry Level Exam
by Sean White (Author)


Whether or not you are taking the NABCEP Entry Level Exam, learning the material covered in this book is the best investment you can make towards your place in the solar industry. This book explains the science of photovoltaics (PV) in a way that most people can understand using the curriculum which reflects the core modules of the NABCEP Entry Level Exam. Providing complete coverage of the NABCEP syllabus in easily accessible chapters, addressing all of the core objectives that will aid in passing the PV Entry Level Exam including the ten main skill sets: PV Markets and Applications Safety Basics Electricity Basics Solar Energy Fundamentals PV Module Fundamentals System Components PV System Sizing Principles PV System Electrical Design PV System Mechanical...

Advances in Concentrating Solar Thermal Research and Technology (Woodhead Publishing Series in Energy)

Advances in Concentrating Solar Thermal Research and Technology (Woodhead Publishing Series in Energy)
by Manuel Blanco (Editor), Lourdes Ramirez Santigosa (Editor)


After decades of research and development, concentrating solar thermal (CST) power plants (also known as concentrating solar power (CSP) and as Solar Thermal Electricity or STE systems) are now starting to be widely commercialized. Indeed, the IEA predicts that by 2050, with sufficient support over ten percent of global electricity could be produced by concentrating solar thermal power plants. However, CSP plants are just but one of the many possible applications of CST systems. Advances in Concentrating Solar Thermal Research and Technology provides detailed information on the latest advances in CST systems research and technology. It promotes a deep understanding of the challenges the different CST technologies are confronted with, of the research that is taking place worldwide to...

Solar Energy Unleashed: How to Save Money by Utilizing Solar Power in Your Home

Solar Energy Unleashed: How to Save Money by Utilizing Solar Power in Your Home
by Mark Johnson (Author)


Solar Energy Unleashed: How to Save Money by Utilizing Solar Power in Your Home!The world is realizing with increasing urgency that our traditional energy sources just aren't cutting it any longer. Solar is finally coming into its own, so learn about it here!
TABLE OF CONTENTS
Chapter 1: Solar Energy Unleashed Chapter 2: Forms of Solar-Powered Energy Chapter 3: Installing Solar Power in Your Home Chapter 4: Other Forms of Natural Energy BONUS: Cutting Out the Waste with Less Energy Usage Click the BUY NOW button to Learn How to Save Money by Utilizing Solar Power in Your Home!

Real Goods Solar Living Sourcebook: Your Complete Guide to Living beyond the Grid with Renewable Energy Technologies and Sustainable Living

Real Goods Solar Living Sourcebook: Your Complete Guide to Living beyond the Grid with Renewable Energy Technologies and Sustainable Living
by John Schaeffer (Author)


What book would you want if you were stranded on a desert island? Widely regarded as the "bible" of off-grid living, Real Goods Solar Living Source Book might be your best choice. With over six hundred thousand copies in print worldwide, it is the most comprehensive resource available for anyone interested in lessening their environmental footprint or increasing their energy independence.The Solar Living Sourcebook, Fourteenth Edition is the ultimate guide to renewable energy, sustainable living, natural and green building, off-grid living, and alternative transportation, written by experts with decades of experience and a passion for sharing their knowledge. This fully revised and updated edition includes brand new sections on permaculture and urban homesteading and completely rewritten...

© 2017 BrightSurf.com