Photovoltaic Electricity: Materials and Markets

The direct conversion of sunlight into electricity using photovoltaics (PV) has already passed the economic break-even point compared to other sources of electricity generation, in many parts of the world. This has been made possible by a combination of factors: significant technical progress in materials and components, enabling conversion efficiencies to be increased to values close to theoretical limits; a very strong demand for photovoltaic panels, justified by a worldwide drive to reduce CO ₂ emissions; and, finally, colossal investments in plants producing semiconductors, and silicon in particular, and manufacturing cells and modules. On the other hand, even though the photovoltaic cell in operation produces electricity without any discharge into the atmosphere, many current manufacturing processes involve too many critical materials (noble metals, Pb...) or operations that require the use of chemicals, toxic gases and energy-intensive treatments.

This article presents the various processes involved in the production of photovoltaic devices, focusing on the materials used and the associated technologies. The manufacturing processes for photovoltaic components, which are closely linked to the use of radiation-absorbing materials (inorganic semiconductors, polymers, etc.) for conversion, will be described in detail, and a number of technological and ecological hurdles still to be overcome will be mentioned. Current and potential conversion efficiencies of photovoltaic components will be presented and discussed.