High-efficiency silicon solar cells by low-cost rapid thermal processing, screen printing, and plasma-enhanced chemical vapor deposition

This paper presents, for the first time, the successful integration of three rapid, low-cost, high-throughput techniques for crystalline Si cell fabrication, namely: rapid thermal processing (RTP) for simultaneous diffusion of a phosphorus emitter and aluminum back-surface-field; screen-printing (SP) for the front grid contact; and low-temperature PECVD of SiN for antireflection and surface passivation. This combination has resulted in 4 cm² cells with efficiencies of 16.3% and 15.9% on 2 Ω-cm FZ and Cz, respectively, as well as 15.4% efficient, 25 cm² FZ cells. Despite the respectable RTP/SP efficiencies, cells formed by conventional furnace processing and photolithography (CFP/PL) give ~2% (abs.) greater efficiencies. Through in-depth modeling and characterization, this difference is quantified on the basis of emitter design, grid shading, and quality of contacts