Zusammenfassung: | |
We measure surface recombination velocities (SRVs) below 10 cm/s on low-resistivity (1.4 Ωcm) p-type crystalline silicon wafers passivated with plasma-assisted and thermal atomic layer deposited (ALD) aluminium oxide (Al2O3) films. Ultrathin Al2O3 films (< 5 nm) are particularly relevant for the implementation into solar cells, as the deposition rate of the ALD process is very low compared to e.g. plasma-enhanced chemical vapor deposition (PECVD). Hence, we examine the passivation quality of a stack consisting of an ultrathin Al2O 3 passivation layer deposited by ALD and a SiNx capping layer deposited by PECVD. Our experiments show a substantial improvement of the thermal stability during firing at 810°C for the Al2O 3/SiNx stacks compared to a single Al2O 3 layer. We report on a 'regeneration effect' observed for Al 2O3 single layers after firing, where the degraded passivation is significantly improved after annealing at 400°C and also by illumination at room temperature using a halogen lamp. Nevertheless, for Al 2O3/SiNx stacks we measure SRVs < 15 cm/s after firing, whereas for Al2O3 single layers the regenerated SRVs are in the range of 10-30 cm/s. Al2O 3/SiNx stacks are hence ideally suited for the implementation into industrial-type silicon solar cells, although 'regenerated' Al2O3 single layers should result in a comparable cell performance.
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Lizenzbestimmungen: | CC BY-NC-ND 3.0 Unported - https://creativecommons.org/licenses/by-nc-nd/3.0/ |
Publikationstyp: | Article |
Publikationsstatus: | publishedVersion |
Erstveröffentlichung: | 2011 |
Schlagwörter (englisch): | Aluminum oxide, Silicon, Solar cells, Surface passivation, Aluminium oxide, Aluminum oxides, Atomic layer deposited, Capping layer, Cell performance, Crystalline silicon wafers, Halogen lamps, P-type, Passivation layer, Room temperature, Single layer, Surface passivation, Surface recombination velocities, Ultra-thin, Chemical vapor deposition, Crystalline materials, Oxide films, Oxides, Passivation, Photovoltaic effects, Plasma deposition, Plasma enhanced chemical vapor deposition, Semiconducting silicon compounds, Silicon nitride, Silicon wafers, Thermodynamic stability, Ultrathin films, Aluminum |
Fachliche Zuordnung (DDC): | 530 | Physik |
Kontrollierte Schlagwörter: | Konferenzschrift |
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