Impact of Nickel Silicide Rear Metallization on the Series Resistance of Crystalline Silicon Solar Cells

摘要

The silicon-based solar cell is one of the most important enablers toward high-efficiency, low-cost clean energy resources. Metallization of silicon-based solar cells typically utilizes screen-printed silver-aluminum (Ag-Al), which improves the cells electrical performance. To date, metal silicide-based ohmic contacts are occasionally used as an alternative candidate only to the front-contact grid lines in crystalline silicon (c-Si)-based solar cells. In this study, we investigate the electrical characteristics of nickel mono-silicide (NiSi)/Cu-Al ohmic contact on the rear side of c-Si solar cells. We observe a significant enhancement in the fill factor of approximately 6.5% for NiSi/Cu-Al rear contacts, thereby leading to an increase in the efficiency by 1.2% compared to Ag-Al. This is attributed to the improvement of the parasitic resistance in which the series resistance decreased by 0.737 Omega cm(-2). Further, we complement experimental observation with a simulation of different contact resistance values, which shows the NiSi/Cu-Al rear contact to be a promising low-cost metallization for c-Si solar cells with enhanced efficiency.