ABSTRACT
Damage of the hydrogenated amorphous/crystalline silicon interface passivation during transparent conductive oxide sputtering is reported. This occurs in the fabrication process of silicon heterojunction solar cells. We observe that this damage is at least partially caused by luminescence of the sputter plasma. Following low-temperature annealing, the electronic interface properties are recovered. However, the silicon-hydrogen configuration of the amorphous silicon film is permanently changed, as observed from infra-red absorbance spectra. In silicon heterojunction solar cells, although the as-deposited film's microstructure cannot be restored after sputtering, no significant losses are observed in their open-circuit voltage.
The authors gratefully acknowledge Loris Barraud, Jonas Geissbühler, and Johannes Seif for their technical contribution and fruitful discussions, as well as Jakub Holovsky for the ATR-FTIR setup. This work was partially supported by Axpo Naturstrom Fonds by the European Commission's 7th FP [FP/2007-2013] under the 20 Plus Project (Grant Agreement No. 256695) and by the Swiss Federal Office for Energy.
