Review of silicon recovery in the photovoltaic industry

The photovoltaic industry is developing rapidly to support the net-zero energy transition. Among various photovoltaic technologies, silicon-based technology is the most advanced, commanding a staggering 95% market share. However, the energy-intensive process of manufacturing silicon wafer raises concerns. In the photovoltaic supply chain, a substantial amount of photovoltaic secondary silicon-containing resource (PV-SSCR), including metallurgical-grade silicon refined slag (MGSRS), silicon fume (SF), silicon cutting waste (SCW) and end-of-life silicon solar cell (ESSC) from discharged modules, can be recycled. Recycling holds the potential to enhance economic value and reduce the overall environmental impacts associated with the lifecycle of silicon photovoltaics. This article offers a comprehensive overview of techniques and applications of four kinds of PV-SSCR: MGSRS, SF, SCW, and ESSC. Moreover, it also highlights challenges and opportunities for further research and development in this field.