Low-cost solar grade silicon powder through iterative gettering of thermally treated porous silicon

•The purity Metallurgical Grade Silicon powder must be enhanced to increase their functionality.•Therefore, we present in this work a new alternative approaches to purify the (MG-Si).•This approach is based on an iterative gettering (IG).

The purity Metallurgical Grade Silicon powder (MG-Si) must be enhanced to increase their functionality for various applications. Therefore, we present in this work a new alternative approaches to purify the (MG-Si). This approach is based on an iterative gettering (IG) which consist to create a sacrificial porous silicon (PS) layer on the top surface of silicon grain, followed by rapid thermal processing (RTP) in an infrared furnace at 900 °C under O2 ambient and then etched with diluted acids. Surface morphology and chemical composition of the treated samples were analyzed by scanning electronic microscopy (SEM), energy dispersive X-ray (EDAX) spectroscopy and inductively coupled plasma associated to Atomic emission spectroscopy (ICP-AES) analysis. The effect of the purification process on the optical properties of MG-Si was evaluated by the PL spectroscopy. The results indicate that Si powder purity was successfully recovered to become as high as 6 N purity.

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