Exploring low temperature-sputtered indium tin oxide (ITO) as an anti-reflection layer for silicon solar cells

This paper tackles challenges in silicon (Si) solar cells, specifically the use of hazardous Phosphorus Oxychloride (POCl3) for emitter formation and silane/ammonia for the Anti-Reflective Coating (ARC) layer, accompanied by high-temperature metallization. The study proposes an eco-friendly ARC layer process, replacing toxic materials. Indium Tin Oxide (ITO) with a refractive index of similar to 2.0 is suggested as a non-toxic substitute for SiNx in the ARC layer. ITO enables fine-tuning of optical parameters and, with its electrical properties, supports low-resistivity contacts through efficient, low-temperature metallization processes. ITO-passivated solar cells with Ag polymer paste as a front contact exhibit promising characteristics: a commendable photocurrent density (J(sc)) of 20 mA cm(-2) at 850 degrees C, low series resistance (R-s) of 1.9 Omega, and high shunt resistance (R-shunt) of 28.9 Omega, as demonstrated by illuminated I-V measurements. Implementing ITO as the ARC on a less toxic emitter junction enhances Si solar cells' current density gain, minimizing current leakage during high-temperature processing. In conclusion, adopting less toxic materials and employing low-temperature processing in passive silicon solar cell fabrication presents an attractive alternative for cost reduction and contributes to environmentally sustainable practices in green manufacturing.