Details
| Original language | English |
|---|---|
| Pages (from-to) | 291-297 |
| Number of pages | 7 |
| Journal | Physica Status Solidi (A) Applications and Materials Science |
| Volume | 212 |
| Issue number | 2 |
| Publication status | Published - Feb 2015 |
Abstract
In this work, we report on fully ion implanted 156 × 156mm2 n-type PERT solar cells fabricated in an industry-capable process. The implant damage of phosphorous and boron was coannealed in a single furnace annealing step. The cells feature a screen-printed front side metallization and an evaporated rear side metallization. The influence of boron emitter profile on the open-circuit voltage VOC and the short-circuit current density JSC was studied by comparing two boron doses (2.5×1015cm-2, 3×1015cm-2) and two annealing durations (20 min, 80 min). The solar cells reach tightly distributed efficiencies above 20% (20.3% maximum). Cells featuring an emitter implanted with 2.5×1015 cm-2 boron dose annealed for 80 min show the highest open-circuit voltages up to 668mV. As compared to implied open-circuit voltages measured on non-metallized cell precursors, this corresponds to a metallization-induced voltage loss of 14mV. For the shorter annealing time (corresponding to a shallower profile) but same boron dose, the VOC loss is 18mV. The fact that the cells with the higher boron dose of 3×1015cm-2 showed lower VOC values indicates that the recombination at the Ag/Al-p+ Si contacts is not totally dominating. We determine the recombination current densities of the metallized emitter regions to 900-1900 fAcm-2. Contrary to the dependence of VOC on the emitter profile, JSC is lower for deeper emitters. The loss in JSC is visible in the internal quantum efficiencies IQE at short wavelengths. Strategies for an optimization of both quantities, JSC and VOC, are discussed.
Keywords
- Boron emitters, Ion implantation, Silicon, Solar cells
ASJC Scopus subject areas
- Materials Science(all)
- Electronic, Optical and Magnetic Materials
- Physics and Astronomy(all)
- Condensed Matter Physics
- Physics and Astronomy(all)
- Surfaces and Interfaces
- Materials Science(all)
- Surfaces, Coatings and Films
- Engineering(all)
- Electrical and Electronic Engineering
- Materials Science(all)
- Materials Chemistry
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In: Physica Status Solidi (A) Applications and Materials Science, Vol. 212, No. 2, 02.2015, p. 291-297.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Influence of the boron emitter profile on VOC and JSC losses in fully ion implanted n-type PERT solar cells
AU - Kiefer, Fabian
AU - Peibst, Robby
AU - Ohrdes, Tobias
AU - Dullweber, Thorsten
AU - Krügener, Jan
AU - Osten, H. Jörg
AU - Schöllhorn, Claus
AU - Grohe, Andreas
AU - Brendel, Rolf
PY - 2015/2
Y1 - 2015/2
N2 - In this work, we report on fully ion implanted 156 × 156mm2 n-type PERT solar cells fabricated in an industry-capable process. The implant damage of phosphorous and boron was coannealed in a single furnace annealing step. The cells feature a screen-printed front side metallization and an evaporated rear side metallization. The influence of boron emitter profile on the open-circuit voltage VOC and the short-circuit current density JSC was studied by comparing two boron doses (2.5×1015cm-2, 3×1015cm-2) and two annealing durations (20 min, 80 min). The solar cells reach tightly distributed efficiencies above 20% (20.3% maximum). Cells featuring an emitter implanted with 2.5×1015 cm-2 boron dose annealed for 80 min show the highest open-circuit voltages up to 668mV. As compared to implied open-circuit voltages measured on non-metallized cell precursors, this corresponds to a metallization-induced voltage loss of 14mV. For the shorter annealing time (corresponding to a shallower profile) but same boron dose, the VOC loss is 18mV. The fact that the cells with the higher boron dose of 3×1015cm-2 showed lower VOC values indicates that the recombination at the Ag/Al-p+ Si contacts is not totally dominating. We determine the recombination current densities of the metallized emitter regions to 900-1900 fAcm-2. Contrary to the dependence of VOC on the emitter profile, JSC is lower for deeper emitters. The loss in JSC is visible in the internal quantum efficiencies IQE at short wavelengths. Strategies for an optimization of both quantities, JSC and VOC, are discussed.
AB - In this work, we report on fully ion implanted 156 × 156mm2 n-type PERT solar cells fabricated in an industry-capable process. The implant damage of phosphorous and boron was coannealed in a single furnace annealing step. The cells feature a screen-printed front side metallization and an evaporated rear side metallization. The influence of boron emitter profile on the open-circuit voltage VOC and the short-circuit current density JSC was studied by comparing two boron doses (2.5×1015cm-2, 3×1015cm-2) and two annealing durations (20 min, 80 min). The solar cells reach tightly distributed efficiencies above 20% (20.3% maximum). Cells featuring an emitter implanted with 2.5×1015 cm-2 boron dose annealed for 80 min show the highest open-circuit voltages up to 668mV. As compared to implied open-circuit voltages measured on non-metallized cell precursors, this corresponds to a metallization-induced voltage loss of 14mV. For the shorter annealing time (corresponding to a shallower profile) but same boron dose, the VOC loss is 18mV. The fact that the cells with the higher boron dose of 3×1015cm-2 showed lower VOC values indicates that the recombination at the Ag/Al-p+ Si contacts is not totally dominating. We determine the recombination current densities of the metallized emitter regions to 900-1900 fAcm-2. Contrary to the dependence of VOC on the emitter profile, JSC is lower for deeper emitters. The loss in JSC is visible in the internal quantum efficiencies IQE at short wavelengths. Strategies for an optimization of both quantities, JSC and VOC, are discussed.
KW - Boron emitters
KW - Ion implantation
KW - Silicon
KW - Solar cells
UR - http://www.scopus.com/inward/record.url?scp=85027924305&partnerID=8YFLogxK
U2 - 10.1002/pssa.201431118
DO - 10.1002/pssa.201431118
M3 - Article
AN - SCOPUS:85027924305
VL - 212
SP - 291
EP - 297
JO - Physica Status Solidi (A) Applications and Materials Science
JF - Physica Status Solidi (A) Applications and Materials Science
SN - 1862-6300
IS - 2
ER -