High-Throughput Temporal ALD Al2O3 Passivation as Rear Surface Passivation for Industrial Local Al BSF Si Solar Cells

26th European Photovoltaic Solar Energy Conference and Exhibition; 1739-1741
A high-throughput temporal atomic layer deposition (ALD) Al2O3 reactor is screened for rear surface passivation of Si passivated emitter and rear cells (PERCs). It is shown that using (i) an Al2O3 layer ≤ 10 nm, (ii) outgassed above 500 °C, and (iii) capped with SiNx as rear surface passivation stack for large area screen-printed p-type Si PERC, leads to an average open circuit voltage (Voc) of 644 mV. There is an obvious gain in Voc of 6.5 mV compared to SiOx passivated PERC, thanks to enhanced rear surface passivation.