Extremely low surface recombination velocities on heavily doped planar and textured p+ silicon using low-temperature positively-charged PECVD SiOx/SiNx dielectric stacks with optimised antireflective properties

Abstract

We present state-of-the-art results on boron emitter passivation (J0e < 25 fA/cm2 and Sn0 < 400 cm/s) with industrially fired positively-charged low-temperature PECVD SiOx/SiNx dielectric stacks deposited in an industrial reactor. These films feature a very low fixed charge density (∼ + 6×1010 cm-2) and excellent interface quality (Dit, midgap of ∼3×1010 eV-1 cm -2) after an industrial firing step. Based on contactless corona-voltage measurements and device simulation, we explain the mechanism of surface passivation to be dominated by chemical passivation rather than field-effect passivation. With excellent optical and passivation properties, these films are suitable for high-efficiency cost-effective industrial n-type silicon wafer solar cells. © 2013 IEEE.