Refractive index graded anti-reflection coating for solar cells based on low cost reclaimed silicon

To meet the demands of the high efficiency and low cost of the photovoltaic industry, it has focused attention on more cost effective silicon cells and cells with a significantly lower energy payback time. In this study, silicon substrates, reclaimed from the integrated circuit industry via polishing and etching treatments, are used after the wet etching process for the surface texturing. An advanced refractive index (RI) graded anti-reflection coating (ARC) is developed based on the stacked depositions of a group of multi silicon nitride nano layers, using an SPTS Plasma Enhanced Chemical Vapor Deposition (PECVD) system. Compared to the cell with single RI ARC, the reclaimed silicon wafers with the novel graded RI ARC have shown a significantly enhanced cell performance. The short circuit current, open circuit voltage, max output power, and fill factor were increased by 7.16%, 4.17%, 30.1% and 15.6%, respectively, based on the low cost reclaimed silicon substrates.