Hot Carrier Solar Cell: Implementation of the Ultimate Photovoltaic Converter
Results and Publications
Start Date: September 2008
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Investigators
Gavin Conibeer, Martin A. Green, University of New South Wales, Sydney; Antonio Marti and Antonio Luque, Instituto de Energia Solar, Madrid; Jean-Francois Guillemoles, Centre National de la Recherche Scientifique (CNRS); Timothy Schmidt, University of Sydney
Objective
This research aims to develop, for the first time, a proof-of-concept device of a hot carrier solar cell using abundant and non-toxic materials, and having a design compatible with thin-film deposition processes. Hot carrier solar cells have the prospect to achieve extremely high light-to-electricity energy conversion efficiency and have a structure that is conceptually simple compared to other very high efficiency devices such as multijunction monolithic tandem cells. They represent one of the most promising photovoltaic concepts to dramatically reduce the cost of solar energy.
Background
The hot carrier solar cell concept belongs to the so-called “third generation” solar cell technologies that investigate photovoltaic conversion schemes with the potential to reach efficiencies substantially higher than the theoretical efficiency limit for traditional single-junction devices (31%). In this scheme, solar-to-electricity energy conversion is enhanced by reducing energy losses related to the absorption of solar photons with energy larger than the bandgap EBG of the active photovoltaic material. Subsequent to the absorption of a photon with energy Eph>EBG, an electron of the valence band is promoted to an excited state in the conduction band that naturally decays to the bottom of the conduction energy band on a timescale of tens of picoseconds.