Details
| Original language | English |
|---|---|
| Pages (from-to) | 307-312 |
| Number of pages | 6 |
| Journal | Energy Procedia |
| Volume | 8 |
| Publication status | Published - 2011 |
Abstract
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.
Keywords
- Aluminum oxide, Silicon, Solar cells, Surface passivation
ASJC Scopus subject areas
- Energy(all)
- General Energy
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In: Energy Procedia, Vol. 8, 2011, p. 307-312.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Comparison of the thermal stability of single Al2O3 layers and Al2O3/SiNx stacks for the surface passiviation of silicon
AU - Veith, Boris
AU - Werner, Florian
AU - Zielke, Dimitri
AU - Brendel, Rolf
AU - Schmidt, Jan
N1 - Funding Information: Funding was provided by the State of Lower Saxony and the German Ministry for the Environment,
PY - 2011
Y1 - 2011
N2 - 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.
AB - 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.
KW - Aluminum oxide
KW - Silicon
KW - Solar cells
KW - Surface passivation
UR - http://www.scopus.com/inward/record.url?scp=80052096838&partnerID=8YFLogxK
U2 - 10.1016/j.egypro.2011.06.141
DO - 10.1016/j.egypro.2011.06.141
M3 - Article
AN - SCOPUS:80052096838
VL - 8
SP - 307
EP - 312
JO - Energy Procedia
JF - Energy Procedia
SN - 1876-6102
ER -