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Projects: Projects for Investigator
Reference Number EP/F050526/1
Title Improved multi-crystalline silicon for solar cell applications
Status Completed
Energy Categories Renewable Energy Sources(Solar Energy, Photovoltaics) 100%;
Research Types Basic and strategic applied research 100%
Science and Technology Fields PHYSICAL SCIENCES AND MATHEMATICS (Metallurgy and Materials) 100%
UKERC Cross Cutting Characterisation Not Cross-cutting 100%
Principal Investigator Dr JD Murphy
No email address given
Materials
University of Oxford
Award Type Standard
Funding Source EPSRC
Start Date 01 April 2008
End Date 31 March 2013
Duration 60 months
Total Grant Value £1
Industrial Sectors No relevance to Underpinning Sectors
Region South East
Programme Materials, Mechanical and Medical Eng
 
Investigators Principal Investigator Dr JD Murphy , Materials, University of Oxford (100.000%)
Web Site
Objectives
Abstract Global warming and the depletion of fossil fuel reserves mean that one of the biggest issues facing humanity is to develop sustainable energy sources. The solar radiation incident upon the Earth in 15 minutes is equivalent to the current annual energy requirements of the entire world's population, so the capture of a tiny fraction of this would go a long way to meeting global demand. The Sun's power is most often harnessed by solar cells, but substantial improvements are needed to make them economically competitive.When solar cells absorb sunlight, the links between some electrons in the material and the atoms to which they are bound are broken. These electrons move freely to an external electrical circuit where they deliver power. In ideal cells, every free electron provides power, but, in practice, some electrons fall into the gaps (holes) created when other electrons are liberated. This process leads to reduced electrical efficiency and is strongly influenced by the presence of metallic impurities and physical imperfections in the silicon. This project will develop novel processing methods to minimise the effects of impurities and imperfections, allowing less pure (hence cheaper) silicon to be used to produce solar cells that are both more efficient and cheaper.In this proposal several novel methods are proposed which allow the removal or controlled re-distribution of these harmful imperfections and impurities from cast silicon, the material from which the majority of solar cells are made. These methods include (i) developing a chemical process which permanently removes certain crystal imperfections and the impurities attached to them from the material, (ii) developing a cheap long low temperature thermal treatment which transports these impurities to regions in which they are less detrimental to the solar cell's efficiency and (iii) using existing damage created at the wafer's surface when it is sliced to trap impurities, meaning that when this surface layer is subsequently removed, the impurities are also removed. The methods proposed have the potential to provide highly significant improvements to solar cell technology allowing more efficient cells to be produced from cheaper, more contaminated starting material than at present
Publications (none)
Final Report (none)
Added to Database 03/11/11