Science Current Events | Science News |

New Material Promises Better Solar Cells

February 13, 2013
Researchers at the Vienna University of Technology show that a recently discovered class of materials can be used to create a new kind of solar cell.

Single atomic layers are combined to create novel materials with completely new properties. Layered oxide heterostructures are a new class of materials, which has attracted a great deal of attention among materials scientists in the last few years. A research team at the Vienna University of Technology, together with colleagues from the USA and Germany, has now shown that these heterostructures can be used to create a new kind of extremely efficient ultra-thin solar cells.

Discovering New Material Properties in Computer Simulations

"Single atomic layers of different oxides are stacked, creating a material with electronic properties which are vastly different from the properties the individual oxides have on their own", says Professor Karsten Held from the Institute for Solid State Physics, Vienna University of Technology. In order to design new materials with exactly the right physical properties, the structures were studied in large-scale computer simulations. As a result of this research, the scientists at TU Vienna discovered that the oxide heterostructures hold great potential for building solar cells.

Turning Light into Electricity

The basic idea behind solar cells is the photoelectric effect. Its simplest version was already explained by Albert Einstein in 1905: when a photon is absorbed, it can cause an electron to leave its place and electric current starts to flow. When an electron is removed, a positively charged region stays behind - a so called "hole". Both the negatively charged electrons as well as the holes contribute to the electrical current.

"If these electrons and holes in the solar cell recombine instead of being transported away, nothing happens and the energy cannot be used", says Elias Assmann, who carried out a major part of the computer simulations at TU Vienna. "The crucial advantage of the new material is that on a microscopic scale, there is an electric field inside the material, which separates electrons and holes." This increases the efficiency of the solar cell.

Two Isolators Make a Metal

The oxides used to create the material are actually isolators. However, if two appropriate types of isolators are stacked, an astonishing effect can be observed: the surfaces of the material become metallic and conduct electrical current. "For us, this is very important. This effect allows us to conveniently extract the charge carriers and create an electrical circuit", says Karsten Held. Conventional solar cells made of silicon require metal wires on their surface to collect the charge carriers - but these wires block part of the light from entering the solar cell.

Not all photons are converted into electrical current with the same efficiency. For different colors of light, different materials work best. "The oxide heterostructures can be tuned by choosing exactly the right chemical elements", says Professor Blaha (TU Vienna). In the computer simulations, oxides containing Lanthanum and Vanadium were studied, because that way the materials operate especially well with the natural light of the sun. "It is even possible to combine different kinds of materials, so that different colors of light can be absorbed in different layers of the solar cell at maximum efficiency", says Elias Assmann.

Putting Theory into Practice

The team from TU Vienna was assisted by Satoshi Okamoto (Oak Ridge National Laboratory, Tennessee, USA) and Professor Giorgio Sangiovanni, a former employee of TU Vienna, who is now working at Würzburg University, Germany. In Würzburg, the new solar cells will now be build and tested. "The production of these solar cells made of oxide layers is more complicated than making standard silicon solar cells. But wherever extremely high efficiency or minimum thickness is required, the new structures should be able to replace silicon cells", Karsten Held believes.

Vienna University of Technology

Related Solar Cells Current Events and Solar Cells News Articles

Molecular nanoribbons as electronic highways
Physicists at Umeå University have, together with researchers at UC Berkeley, USA, developed a method to synthesise a unique and novel type of material which resembles a graphene nanoribbon but in molecular form.

Research improves efficiency from larger perovskite solar cells
Using a newly developed fabrication method, a research team has attained better than a 15-percent energy conversion efficiency from perovskite solar cells larger than one square centimeter area.

Graphene as a front contact for silicon-perovskite tandem solar cells
Teams at HZB have already acquired extensive experience with these kinds of tandem cells. A particularly effective complement to conventional silicon is the hybrid material called perovskite.

Invisibility cloak might enhance efficiency of solar cells
Success of the energy turnaround will depend decisively on the extended use of renewable energy sources. However, their efficiency partly is much smaller than that of conventional energy sources.

Physicists defy conventional wisdom to identify ferroelectric material
A team of physicists has defied conventional wisdom by inducing stable ferroelectricity in a sheet of strontium titanate only a few nanometers thick.

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.

New efficiency record for solar hydrogen production is 14 percent
Solar energy is abundantly available globally, but unfortunately not constantly and not everywhere. One especially interesting solution for storing this energy is artificial photosynthesis.

SLAC's ultrafast 'electron camera' visualizes ripples in 2-D material
New research led by scientists from the Department of Energy's SLAC National Accelerator Laboratory and Stanford University shows how individual atoms move in trillionths of a second to form wrinkles on a three-atom-thick material.

New nanomaterial maintains conductivity in three dimensions
An international team of scientists has developed what may be the first one-step process for making seamless carbon-based nanomaterials that possess superior thermal, electrical and mechanical properties in three dimensions.

CWRU researchers efficiently charge a lithium-ion battery with solar cell
Consumers aren't embracing electric cars and trucks, partly due to the dearth of charging stations required to keep them moving.
More Solar Cells Current Events and Solar Cells News Articles

The Physics of Solar Cells (Properties of Semiconductor Materials)

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

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 text explains the terms and concepts of solar cell device physics and shows the reader how to formulate and solve relevant physical problems. Exercises and worked solutions are included. Contents: Photons In, Electrons Out: Basic Principles of PV; Electrons and Holes in Semiconductors; Generation and Recombination; Junctions; Analysis of the p n Junction; Monocrystalline Solar Cells; Thin Film...

Build Your Own Solar Panel: Generate Electricity from the Sun.

Build Your Own Solar Panel: Generate Electricity from the Sun.
by Phillip Hurley (Author)

Whether you're trying to get off the grid, or you just like to experiment, Build Your Own Solar Panel has all the information you need to build your own photovoltaic panel to generate electricity from the sun. Now available for the first time in print, this revised and expanded edition has easy-to-follow directions, and over 150 detailed photos and illustrations. Lists of materials, tools, and suppliers of PV cells are included. Every-day tools are all that you need to complete these projects.
Build Your Own Solar Panel will show you how to:
Design and build PV panels,
Customize panel output,
Make tab and bus ribbon,
Solder cell connections,
Wire a photovoltaic panel,
Purchase solar cells,
Test and rate PV cells,
Repair damaged solar cells,

Physics of Solar Cells: From Basic Principles to Advanced Concepts

Physics of Solar Cells: From Basic Principles to Advanced Concepts
by Peter Würfel (Author)

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 efficiency. Requiring no more than standard physics knowledge, the book enables both students and researchers to understand the factors driving conversion efficiency and to apply this knowledge to their own solar cell development. New exercises after each chapter help students to consolidate their freshly acquired knowledge, while the book also serves as a reference for researchers already working in this...

Build A Solar Hydrogen Fuel Cell System

Build A Solar Hydrogen Fuel Cell System
by Phillip Hurley (Author)

Learn how to construct and operate the components of a solar hydrogen fuel cell system: the fuel cell stack, the electrolyzer to generate hydrogen fuel, simple hydrogen storage, and solar panels designed specifically to run electrolyzers for hydrogen production. Complete, clear, illustrated instructions to build all the major components make it easy for the non-engineer to understand and work with this important new technology. Featured are the author's innovative and practical designs for efficient solar powered hydrogen production including: ESPMs (Electrolyzer Specific Photovoltaic Modules) – 40 watt solar panels designed specifically to run electrolyzers efficiently; a 40-80 watt electrolyzer for intermittant power from renewable energy sources such as solar and wind; and, a 6-12...

Practical Photovoltaics: Electricity from Solar Cells, 3rd Edition

Practical Photovoltaics: Electricity from Solar Cells, 3rd Edition
by Richard J. Komp (Author), John Perlin (Foreword)

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 solar electricity, as well as a detailed installation and maintenance manual. A well-illustrated appendix offers step-by-step instructions for constructing your own solar module, a creative approach to demystifying the technology. Presented in a clear, concise, and understandable style, Dr. Komp's contribution to PV literature has been called the "best single reference available," "the easiest and...

Solar Cell & Energy Guide

Solar Cell & Energy Guide
by Silicon Solar

Solar Cell Book

The solar cell book is an information packet on the basics of solar energy. The topics that are covered in the solar cell book are vast but brief. There is just enough information to help you understand how solar cells and solar power work in order to fully understand how everything works you’d need a lot bigger book. There is also information on interconnecting solar cells along with various diagrams that help you understand the ins and outs of solar cells. There is also a class project section with various degrees of difficulty that range from elementary to intermediate levels.

Topics Covered:

PV Terminology
Solar Cell
PV Modules
PV Array
Peak Watt (Wp)
Diamond Solar Cells
Interconnecting Solar Cells
Build Your Own Fuel Cells

Build Your Own Fuel Cells
by Phillip Hurley (Author)

The technology of the future is here today - and now available to the non-engineer! Build Your Own Fuel Cells contains complete, easy to understand illustrated instructions for building several types of proton exchange membrane (PEM) fuel cells - and, templates for 6 PEM fuel cell types, including convection fuel cells and oxygen-hydrogen fuel cells, in both single slice and stacks. Low tech/high quality Two different low-tech fuel cell construction methods are covered: one requires a bandsaw and drill press, and the other only a few hand tools. Anyone with minimum skills and tools will be able to produce high quality fuel cells from readily obtainable materials - contact info for materials suppliers is included. Electrolyzers and MEAs Build Your Own Fuel Cells includes a detailed...

Solar II: How to Design, Build and Set Up Photovoltaic Components and Solar Electric Systems

Solar II: How to Design, Build and Set Up Photovoltaic Components and Solar Electric Systems
by Phillip Hurley (Author)

Now that you've built your solar panels, how do you set up a photovoltaic system and plug in? In Solar II, Phillip Hurley, author of Build Your Own Solar Panel, will show you how to:
Calculate daily electrical usage and needs
Plan and size your solar electric system
Build racks and charge controllers
Mount and orient PV panels
Wire solar panel arrays
Make a ventilated battery box
Wire battery arrays for solar panels
Install an inverter
Maintain solar batteries for optimum life and performance
Make your own combiner box, bus bars, and DC and AC service boxes
Solar II includes easy-to-follow directions with over 150 black & white photos, illustrations and schematics.

Solar Cell Device Physics, Second Edition

Solar Cell Device Physics, Second Edition
by Stephen Fonash (Author)

There has been an enormous infusion of new ideas in the field of solar cells over the last 15 years; discourse on energy transfer has gotten much richer, and nanostructures and nanomaterials have revolutionized the possibilities for new technological developments. However, solar energy cannot become ubiquitous in the world's power markets unless it can become economically competitive with legacy generation methods such as fossil fuels.

The new edition of Dr. Stephen Fonash's definitive text points the way toward greater efficiency and cheaper production by adding coverage of cutting-edge topics in plasmonics, multi-exiton generation processes, nanostructures and nanomaterials such as quantum dots. The book's new structure improves readability by shifting many detailed equations to...

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...

© 2015