Science News & Science Current Events
 
Email a Friend Send to a friend
Printer Friendly Print New efficiency benchmark for dye-sensitized solar cells

New efficiency benchmark for dye-sensitized solar cells

June 30, 2008

In a paper published online June 29 in the journal Nature Materials, EPFL professor Michael Graetzel, Shaik Zakeeruddin and colleagues from the Changchun Institute of Applied Chemistry at the Chinese Academy of Sciences have achieved a record light conversion efficiency of 8.2% in solvent-free dye-sensitized solar cells.

This breakthrough in efficiency without the use of volatile organic solvents will make it possible to pursue large scale, outdoor practical application of lightweight, inexpensive, flexible dye-sensitized solar films that are stable over long periods of light and heat exposure.




Dye-sensitized solar cell technology, invented by Michael Grätzel at EPFL in the 1990s, shows great promise as a cheap alternative to expensive silicon solar cells. Dye-sensitized cells imitate the way that plants and certain algae convert sunlight into energy. The cells are made up of a porous film of tiny (nanometer sized) white pigment particles made out of titanium dioxide. The latter are covered with a layer of dye which is in contact with an electrolyte solution. When solar radiation hits the dye it injects a negative charge in the pigment nanoparticle and a positive charge into the electrolyte resulting in the conversion of sunlight into electrical energy. The cells are inexpensive, easy to produce and can withstand long exposure to light and heat compared with traditional silicon-based solar cells. Currently, state-of-the-art dye-sensitized cells have an overall light conversion efficiency greater than 11%, still about two times lower than silicon cell technology. A major drawback to the dye-sensitized cell technology is the electrolyte solution, which is made up of volatile organic solvents and must be carefully sealed. This, along with the fact that the solvents permeate plastics, has precluded large-scale outdoor application and integration into flexible structures.

To overcome these limitations, Grätzel and his colleagues developed a new concept -- a mixture of three solid salts as an alternative to using organic solvents as an electrolyte solution. When the three solid components are mixed together in the right proportion they turn into a melt showing excellent stability and efficiency. Grätzel is confident that further development of these types of electrolyte mixtures will lead to large-scale practical application of dye-sensitized solar cell technology, reinforcing solar energy's role as a cornerstone of alternative energy production.

Ecole Polytechnique Fédérale de Lausanne



Related Solar Cells Current Events and Solar Cells News Articles Solar Cells Current Events and Solar Cells News RSS Solar Cells Current Events and Solar Cells News RSS
New Graphene-Based Material Clarifies Graphite Oxide Chemistry
A new "graphene-based" material that helps solve the structure of graphite oxide and could lead to other potential discoveries of the one-atom thick substance called graphene, which has applications in nanoelectronics, energy storage and production, and transportation such as airplanes and cars, has been created by researchers at The University of Texas at Austin.

Coating copies microscopic biological surfaces
Someday, your car might have the metallic finish of some insects or the deep black of a butterfly's wing, and the reflectors might be patterned on the nanostructure of a fly's eyes.

Slicing solar power costs
University of Utah engineers devised a new way to slice thin wafers of the chemical element germanium for use in the most efficient type of solar power cells. They say the new method should lower the cost of such cells by reducing the waste and breakage of the brittle semiconductor.

DOE official cites need for major breakthroughs to cope with climate change
Meeting the world's growing energy needs while responding to global warming during the 21st Century will be one of the biggest challenges humanity has ever faced, Raymond L. Orbach, Ph.D., the U.S. Department of Energy's Under Secretary for Science, says in the latest podcast in the American Chemical Society's Global Challenges/Chemistry Solutions series

Polymer electric storage, flexible and adaptable
The proliferation of solar, wind and even tidal electric generation and the rapid emergence of hybrid electric automobiles demands flexible and reliable methods of high-capacity electrical storage. Now a team of Penn State materials scientists is developing ferroelectric polymer-based capacitors that can deliver power more rapidly and are much lighter than conventional batteries.

Flexible nanoantenna arrays capture abundant solar energy
Researchers have devised an inexpensive way to produce plastic sheets containing billions of nanoantennas that collect heat energy generated by the sun and other sources. The technology, developed at the U.S. Department of Energy's Idaho National Laboratory, is the first step toward a solar energy collector that could be mass-produced on flexible materials.

'Nanonet' circuits closer to making flexible electronics reality
Researchers have overcome a major obstacle in producing transistors from networks of carbon nanotubes, a technology that could make it possible to print circuits on plastic sheets for applications including flexible displays and an electronic skin to cover an entire aircraft to monitor crack formation.

A Colorful Approach to Solar Energy
Revisiting a once-abandoned technique, engineers at the Massachusetts Institute of Technology (MIT) have successfully created a sophisticated, yet affordable, method to turn ordinary glass into a high-tech solar concentrator.

Research helps understand factors that influence efficiency of organic-based devices
Organic-based devices, such as organic light-emitting diodes, require a transparent conductive layer with a high work function, meaning it promotes injection of electron holes into an organic layer to produce more light.

Visualizing atomic-scale acoustic wavesin nanostructures
Acoustic waves play many everyday roles - from communication between people to ultrasound imaging. Now the highest frequency acoustic waves in materials, with nearly atomic-scale wavelengths, promise to be useful probes of nanostructures such as LED lights.
More Solar Cells Current Events and Solar Cells News Articles


The Physics of Solar Cells (Properties of Semiconductor Materials) (Properties of Semiconductor Materials)
by Jenny Nelson

This book provides a comprehensive introduction to the physics of the photovoltaic cell. It is suitable for undergraduates, graduate students, and researchers new to the field. It covers: basic physics of semiconductors in photovoltaic devices; physical models of solar cell operation; characteristics and design of common types of solar cell; and approaches to increasing solar cell efficiency. The...



Thin Film Solar Cells: Fabrication, Characterization and Applications (Wiley Series in Materials for Electronic & Optoelectronic Applications)

Thin-film solar cells are either emerging or about to emerge from the research laboratory to become commercially available devices finding practical various applications. Currently no textbook outlining the basic theoretical background, methods of fabrication and applications currently exist. Thus, this book aims to present for the first time an in-depth overview of this topic covering a broad...



Thin-Film Solar Cells: Next Generation Photovoltaics and Its Applications (Springer Series in Photonics)

The first comprehensive book on thin-film solar cells, potentially a key technology for solving the energy production problem in the 21st century in an environmentally friendly way. It covers a wide range of scientific and technological aspects of thin film semiconductors - deposition technologies, growth mechanisms and the basic properties of amorphous and nano-crystalline silicon - as well...



Physics of Solar Cells: From Basic Principles to Advanced Concepts
by Peter Würfel, Uli Würfel

Based on the highly regarded and extremely successful first edition, this thoroughly revised, updated and expanded edition contains the latest knowledge on the mechanisms of solar energy conversion. The textbook describes in detail all aspects of solar cell function, the physics behind every single step, as well as all the issues to be considered when improving solar cells and their...



Practical Photovoltaics: Electricity from Solar Cells
by Richard J. Komp

Practical Photovoltaics, the now-classic reference on solar electricity, offers a unique combination of technical discussion and practical advice. Physicist, lecturer, and solar-home dweller Richard Komp explains the "how" and the "how-to" of PV, while providing valuable information on the industry, new developments, and the future. The book is a comprehensive guide to the theory and reality of...



Crystalline Silicon Solar Cells: Technology and Systems Applications
by Adolf Goetzberger, Joachim Knobloch, Bernhard Voss

As environmental concerns escalate, solar power is increasingly seen as an attractive alternative energy source. Crystalline Silicon Solar Cells addresses the practical and theoretical issues fundamental to the viable conversion of sunlight into electricity. Written by three internationally renowned experts, this valuable reference profits from results and experience gained from research at the...



Solar Cells: Materials, Manufacture and Operation
by Tom Markvart, Luis Castaner

The capture and use of solar energy has been growing for many years, but only in recent times have advances in design and manufacture allowed us to see the incorporation of solar energy as a significant player in the renewable energy arena.Solar cells are at the heart of any photovoltaic system and in this book the various types are described and their characteristics reviewed.Going beyond...



Flexible Solar Cells
by Mario Pagliaro, Giovanni Palmisano, Rosaria Ciriminna

With the decline in the world's natural resources, the need for new and cheaper energy sources is evolving. One such source is the sun which generates heat and light which can be harnessed and used to our advantage. This reference book introduces the topic of photovoltaics in the form of flexible solar cells. There are explanations of the principles behind this technology, the engineering...



Nanostructured Materials for Solar Energy Conversion

Nanostructured Materials for Solar Energy Conversion covers a wide variety of materials and device types from inorganic materials to organic materials. This book deals with basic semiconductor physics, modelling of nanostructured solar cell, nanostructure of conventional solar cells such as silicon, CIS and CdTe, dye-sensitized solar cell, organic solar cell, photosynthetic materials, fullerene,...

Solar Cells: Operating Principles, Technology, and System Applications (Prentice-Hall series in solid state physical electronics)
by Martin A. Green

© 2008 BrightSurf.com