Growth and analysis of polycrystalline silicon ingots using recycled silicon from waste solar module

Abstract

The proliferated growth of the Photovoltaic industry (PV) will eventually lead to unprecedented volumes of silicon-based solar waste. Failing to manage high volumes of waste, can lead to a huge amount of silicon metal loss and is also highly conducive to posing an environmental hazard. Therefore, efficient recovery and re-utilization after proper purification of the PV-waste-based silicon are highly obligatory for the sustainable development of the PV industry. Herein, we report the growth of small-size silicon ingots (φ = 0.5 inch, 1.0 inch) produced from recovered silicon from the waste crystalline silicon (c-Si) solar module through the Spark Plasma Sintering (SPS) technique. The silicon feedstock was prepared, after the extraction of silicon cells from the used panel and chemically etching contacts, ARC (anti-reflection coating), from the cells in order to recover the silicon wafer. The silicon wafer pieces were pulverized to produce very fine powder and subsequently processed at a different set of temperature-pressure for the study of density variation. The highest density (2.33 gm/cm3) equal to the theoretical density of silicon was obtained for sample grown at temperature 1200 °C and pressure 60 MPa. The purity of the obtained ingots was found to be greater than 3 N and therefore, can find use in different industries.