The Physics of High Efficiency Photovoltaic Solar Energy Conversion
University of New South Wales
Photovoltaics is starting to make an impact in large-scale electricity production. Last year, it was the largest source of new electricity production capacity in Europe, ahead of both gas and wind (!), and contributed over 20% to the electricity supply in Germany at the time of peak demand during May 2011. Costs have come down rapidly over the past three years with increasing emphasis on energy conversion efficiency as a way of further reducing costs.
Every photovoltaic researcher knows of the brilliant work of William Shockley and Hans Queisser which very simply derived fundamental efficiency limits on the conversion efficiency of sunlight into electricity using solar cells. Less well known is that this work has been recently extended by Uwe Rau, with the perhaps surprising conclusion that the optical output of any reasonably efficient electroluminescent device can be predicted from ts performance as a photodectector. In trying to understand how to increase optical absorption in a solar cell of limited thickness, Eli Yablonovitch explored the manipulation of optical density of states in semiconductors and initiated the new field of photonic crystals. More recently, it has been shown that plasmonics provides a way of increasing the optical density of states within a solar absorber beyond the limits deduced by Yablonovitch, with this likely to lead to improvements in the optical efficiency of photovoltaic and related deviceas.
The talk will give an overview of the more exciting recent developments in both the applications of Photovoltaics as well as in their physics and show how the latter relate to closely related fields in optoelectronics.
Martin Green is currently a Scientia Professor at the University of New South Wales, Sydney, Australia and Executive Research Director of the University's Photovoltaic Centre of Excellence. His group's contributions to photovoltaics include development of the world’s highest efficiency silicon solar cells and commercialization of several different cell technologies. He is the author of several well known books on solar cells and numerous papers. His work has resulted in many major international awards including the 2002 Right Livelihood Award, commonly known as the Alternative Nobel Prize, the 2007 SolarWorld Einstein Award and the 2009 ENI Award for Renewable and Non Conventional Energy.
Snacks will be provided at 12.00 prior to Colloquium. Leonard Huxley foyer/tea room