Towards sustainable photovoltaics: The search for new materials

Abstract

The opportunities for photovoltaic (PV) solar energy conversion are reviewed in the context of projected world energy demands for the twenty-first century. Conventional single-crystal silicon solar cells are facing increasingly strong competition from thinfilm solar cells based primarily on polycrystalline absorber materials, such as cadmium telluride (CdTe) and copper indium gallium diselenide (CIGS). However, if PVs are to make a significant contribution to satisfy global energy requirements, issues of sustainability and cost will need to be addressed with increased urgency. There is a clear need to expand the range of materials and processes that is available for thin-film solar cell manufacture, placing particular emphasis on low-energy processing and sustainable non-toxic raw materials. The potential of new materials is exemplified by copper zinc tin sulphide, which is emerging as a viable alternative to the more toxic CdTe and the more expensive CIGS absorber materials. © 2011 The Royal Society.