Details
| Original language | English |
|---|---|
| Pages (from-to) | 243-249 |
| Number of pages | 7 |
| Journal | Energy Procedia |
| Volume | 38 |
| Early online date | 5 Sept 2013 |
| Publication status | Published - 2013 |
| Event | 3rd International Conference on Crystalline Silicon Photovoltaics, SiliconPV 2013 - Hamelin, Germany Duration: 25 Mar 2013 → 27 Mar 2013 |
Abstract
Industrial PERC cell process flows typically apply the polishing of the rear side after texturing as well as the edge isolation after POCl3 diffusion. In this paper, we present a novel single step polishing process which we apply post double sided texturing and diffusion in order to remove the rear emitter and to reduce the rear surface roughness. One challenge is to minimize the etch back of the front side emitter during rear side polishing due to the reactive gas phase of the polishing process. By optimizing the polishing process, we are able to limit the increase of the emitter sheet resistance below 5 Ω/sq. However, the wet cleaning post polishing contributes an additional 20 Ω/sq emitter sheet resistance increase which is subject to further optimization. We compensate the emitter sheet resistance increase due to wet cleaning by applying a 45 Ω/sq POCl3 diffusion instead of a 60 Ω/sq diffusion. The resulting PERC solar cells with polished rear surface post texture and diffusion show conversion efficiencies up to 19.6% which is comparable to the reference PERC cells which apply a rear protection layer instead of a polishing process.
Keywords
- Cleaning sequences, PERC solar cells, Screen-printing, Sheet resistance, Wet chemical polishing
ASJC Scopus subject areas
- Energy(all)
- General Energy
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In: Energy Procedia, Vol. 38, 2013, p. 243-249.
Research output: Contribution to journal › Conference article › Research › peer review
}
TY - JOUR
T1 - Wet Chemical Polishing for Industrial Type PERC Solar Cells
AU - Kranz, Christopher
AU - Wyczanowski, Sabrina
AU - Baumann, Ulrike
AU - Weise, Katrin
AU - Klein, Cornelia
AU - Delahaye, Franck
AU - Dullweber, Thorsten
AU - Brendel, Rolf
PY - 2013
Y1 - 2013
N2 - Industrial PERC cell process flows typically apply the polishing of the rear side after texturing as well as the edge isolation after POCl3 diffusion. In this paper, we present a novel single step polishing process which we apply post double sided texturing and diffusion in order to remove the rear emitter and to reduce the rear surface roughness. One challenge is to minimize the etch back of the front side emitter during rear side polishing due to the reactive gas phase of the polishing process. By optimizing the polishing process, we are able to limit the increase of the emitter sheet resistance below 5 Ω/sq. However, the wet cleaning post polishing contributes an additional 20 Ω/sq emitter sheet resistance increase which is subject to further optimization. We compensate the emitter sheet resistance increase due to wet cleaning by applying a 45 Ω/sq POCl3 diffusion instead of a 60 Ω/sq diffusion. The resulting PERC solar cells with polished rear surface post texture and diffusion show conversion efficiencies up to 19.6% which is comparable to the reference PERC cells which apply a rear protection layer instead of a polishing process.
AB - Industrial PERC cell process flows typically apply the polishing of the rear side after texturing as well as the edge isolation after POCl3 diffusion. In this paper, we present a novel single step polishing process which we apply post double sided texturing and diffusion in order to remove the rear emitter and to reduce the rear surface roughness. One challenge is to minimize the etch back of the front side emitter during rear side polishing due to the reactive gas phase of the polishing process. By optimizing the polishing process, we are able to limit the increase of the emitter sheet resistance below 5 Ω/sq. However, the wet cleaning post polishing contributes an additional 20 Ω/sq emitter sheet resistance increase which is subject to further optimization. We compensate the emitter sheet resistance increase due to wet cleaning by applying a 45 Ω/sq POCl3 diffusion instead of a 60 Ω/sq diffusion. The resulting PERC solar cells with polished rear surface post texture and diffusion show conversion efficiencies up to 19.6% which is comparable to the reference PERC cells which apply a rear protection layer instead of a polishing process.
KW - Cleaning sequences
KW - PERC solar cells
KW - Screen-printing
KW - Sheet resistance
KW - Wet chemical polishing
UR - http://www.scopus.com/inward/record.url?scp=84898712246&partnerID=8YFLogxK
U2 - 10.1016/j.egypro.2013.07.273
DO - 10.1016/j.egypro.2013.07.273
M3 - Conference article
AN - SCOPUS:84898712246
VL - 38
SP - 243
EP - 249
JO - Energy Procedia
JF - Energy Procedia
SN - 1876-6102
T2 - 3rd International Conference on Crystalline Silicon Photovoltaics, SiliconPV 2013
Y2 - 25 March 2013 through 27 March 2013
ER -