Industrial high-rate (∼5 nm/s) deposited silicon nitride yielding high-quality bulk and surface passivation under optimum anti-reflection coating conditions

Abstract

High-quality surface and bulk passivation of crystalline silicon solar cells has been obtained under optimum anti-reflection coating properties by silicon nitride (a-SiNx:H) deposited at very high deposition rates of ∼5 nm/s. These a-SiNx:H films were deposited using the expanding thermal plasma (ETP) technology under regular processing conditions in an inline industrial-type reactor with a nominal throughput of 960 solar cells/hour. The low surface recombination velocities (50–70 cm/s) were obtained on p-type silicon substrates (8·4 Ω cm resistivity) for as-deposited and annealed films within the broad refractive index range of 1·9–2·4, which covers the optimum bulk passivation and anti-reflection coating performance reached at a refractive index of ∼2·1. Copyright © 2005 John Wiley & Sons, Ltd.