Effective surface passivation of crystalline silicon using ultrathin Al₂O₃ films and Al₂O₃/SiN _x stacks

verfasst von

Jan Schmidt, Boris Veith, Rolf Brendel

Abstract

We measure surface recombination velocities (SRVs) below 10 cm/s on p-type crystalline silicon wafers passivated by atomic-layer-deposited (ALD) aluminium oxide (Al₂O₃) films of thickness ≥10 nm. For films thinner than 10 nm the SRV increases with decreasing Al₂O₃ thickness. For ultrathin Al₂O₃ layers of 3.6 nm we still attain a SRV < 22 cm/s on 1.5 Ω cm p-Si and an exceptionally low SRV of 1.8 cm/s on high-resistivity (200 Ω cm) p-Si. Ultrathin Al ₂O₃ films are particularly relevant for the implementation into solar cells, as the deposition rate of the ALD process is extremely low compared to the frequently used plasma-enhanced chemical vapour deposition of silicon nitride (SiN_x). Our experiments on silicon wafers passivated with stacks composed of ultrathin Al₂O₃ and SiN _x show that a substantially improved thermal stability during high-temperature firing at 830 °C is obtained for the Al₂O ₃/SiN_x stacks compared to the single-layer Al ₂O₃ passivation. Al₂O₃/SiN _x stacks are hence ideally suited for the implementation into industrial-type silicon solar cells where the metal contacts are made by screen-printing and high-temperature firing of metal pastes.

Externe Organisation(en)

Institut für Solarenergieforschung GmbH (ISFH)

Typ

Artikel

Journal

Physica Status Solidi - Rapid Research Letters

Band

3

Seiten

287-289

Anzahl der Seiten

3

ISSN

1862-6254

Publikationsdatum

2009

Publikationsstatus

Veröffentlicht

Peer-reviewed

Ja

ASJC Scopus Sachgebiete

Werkstoffwissenschaften (insg.), Physik der kondensierten Materie

Elektronische Version(en)

https://doi.org/10.1002/pssr.200903272 (Zugang: Geschlossen)