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 (aSiN x :H) deposited at very high deposition rates of $ 5 nm/s. These a-SiN x :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 (8Á4 cm resistivity) for as-deposited and annealed films within the broad refractive index range of 1Á9-2Á4, which covers the optimum bulk passivation and anti-reflection coating performance reached at a refractive index of $ 2Á1.

Characterisation and optimisation of PECVD SiNx as an antireflection coating and passivation layer for silicon solar cells

“…In relation to this goal, we note that Lauinger et al 9 achieved a saturation of τ eff but by very Si-rich SiN x with n above 2.3, and Hoex et al 38 presented a relatively constant S eff,UL within a refractive index range of 1.9-2.4, however, the S eff,UL associated with their SiN x -passivated p-type 8.4-· cm FZ Si substrates is relatively high (50-70 cm/s). Indeed, within a broad range of n (1.85-4.07) associated with SiN x , a constant low S eff,UL on low resistivity (≤1.1 · cm) Si substrates has not been achieved.…”

High-Quality Surface Passivation Obtained by High-Rate Deposited Silicon Nitride, Silicon Dioxide and Amorphous Silicon using the Versatile Expanding Thermal Plasma Technique

“…The difference in the level of bulk passivation was attributed to a lower mass density of the silicon nitride films deposited by the ETP technique [7]. In the last few years the mass density of the silicon nitride films deposited by the ETP technique was significantly improved by changing the nitrogen containing precursor from N2 to NH3 and by elaborate process optimization [7,8].…”

Electric field induced surface passivation of Si by atomic layer deposited Al<inf>2</inf>O<inf>3</inf> studied by optical second-harmonic generation

“…More details are described in Ref. [21]. The effective lifetime of c-Si passivated by the a-SiNx:H was determined to be 174 us with carrier lifetime spectroscopy (as measured right before the SHG experiments).…”