Details
| Original language | English |
|---|---|
| Article number | 8964568 |
| Pages (from-to) | 423-430 |
| Number of pages | 8 |
| Journal | IEEE journal of photovoltaics |
| Volume | 10 |
| Issue number | 2 |
| Publication status | Published - 22 Jan 2020 |
Abstract
Degradation and regeneration of recombination parameters can occur in the bulk and at the surfaces of silicon solar cells. This article focuses on the time-resolved analysis of the recombination properties of textured 1.7 cm boron-doped p-Type Cz-Si and 5 cm phosphorus-doped n-Type Cz-Si wafers, where the surfaces are passivated by n+ poly-Si on interfacial oxide layers exposed to a rapid thermal annealing (RTA) step in a conventional firing furnace. We observe a thermally activated instability in the lifetime over the entire examined injection range. Our experiments show that minority carrier injection (e.g., by illumination) is not required. Degradation in the surface passivation quality of the poly-Si on oxide layer-corresponding to an increase of the saturation current density J0 by up to a factor of five-causes the degradation of the effective lifetime. Interestingly, the surface passivation fully regenerates under prolonged annealing and finally improves even beyond the initial state. Both the extent of the lifetime degradation and the change in J0 depend on the postprocessing treatment temperature which we varied between 80 and 400 °C. Our results indicate that two different processes are responsible for the degradation and the regeneration. Reference samples which did not receive an RTA treatment show no degradation of the surface passivation quality. The RTA treatment applied therefore triggers the degradation effect. A large improvement of the surface passivation quality under prolonged annealing (e.g., at 400 °C) is observed for all samples examined in this study.
Keywords
- Carrier lifetime, degradation, poly-Si, Poly-Si on oxide (POLO), silicon, surface passivation
ASJC Scopus subject areas
- Materials Science(all)
- Electronic, Optical and Magnetic Materials
- Physics and Astronomy(all)
- Condensed Matter Physics
- Engineering(all)
- Electrical and Electronic Engineering
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In: IEEE journal of photovoltaics, Vol. 10, No. 2, 8964568, 22.01.2020, p. 423-430.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Degradation and Regeneration of n+-Doped Poly-Si Surface Passivation on p-Type and n-Type Cz-Si under Illumination and Dark Annealing
AU - Winter, Michael
AU - Bordihn, Stefan
AU - Peibst, Robby
AU - Brendel, Rolf
AU - Schmidt, Jan
N1 - Funding Information: Manuscript received August 30, 2019; revised October 24, 2019 and November 29, 2019; accepted December 21, 2019. Date of publication January 21, 2020; date of current version February 19, 2020. This work was supported in part by the German State of Lower Saxony and in part by the European Union’s Horizon 2020 Programme for research, technological developments, and demonstration within the research project DISC under Project 727529. (Corresponding author: Michael Winter.) M. Winter, R. Brendel, and J. Schmidt are with the Institute for Solar Energy Research Hamelin/Emmerthal (ISFH), 31860 Emmerthal, Germany, and also with the Institute of Solid-State Physics, Leibniz University Hannover, 30167 Hannover, Germany (e-mail: m.winter@isfh.de; bren-del@isfh.de; j.schmidt@isfh.de).
PY - 2020/1/22
Y1 - 2020/1/22
N2 - Degradation and regeneration of recombination parameters can occur in the bulk and at the surfaces of silicon solar cells. This article focuses on the time-resolved analysis of the recombination properties of textured 1.7 cm boron-doped p-Type Cz-Si and 5 cm phosphorus-doped n-Type Cz-Si wafers, where the surfaces are passivated by n+ poly-Si on interfacial oxide layers exposed to a rapid thermal annealing (RTA) step in a conventional firing furnace. We observe a thermally activated instability in the lifetime over the entire examined injection range. Our experiments show that minority carrier injection (e.g., by illumination) is not required. Degradation in the surface passivation quality of the poly-Si on oxide layer-corresponding to an increase of the saturation current density J0 by up to a factor of five-causes the degradation of the effective lifetime. Interestingly, the surface passivation fully regenerates under prolonged annealing and finally improves even beyond the initial state. Both the extent of the lifetime degradation and the change in J0 depend on the postprocessing treatment temperature which we varied between 80 and 400 °C. Our results indicate that two different processes are responsible for the degradation and the regeneration. Reference samples which did not receive an RTA treatment show no degradation of the surface passivation quality. The RTA treatment applied therefore triggers the degradation effect. A large improvement of the surface passivation quality under prolonged annealing (e.g., at 400 °C) is observed for all samples examined in this study.
AB - Degradation and regeneration of recombination parameters can occur in the bulk and at the surfaces of silicon solar cells. This article focuses on the time-resolved analysis of the recombination properties of textured 1.7 cm boron-doped p-Type Cz-Si and 5 cm phosphorus-doped n-Type Cz-Si wafers, where the surfaces are passivated by n+ poly-Si on interfacial oxide layers exposed to a rapid thermal annealing (RTA) step in a conventional firing furnace. We observe a thermally activated instability in the lifetime over the entire examined injection range. Our experiments show that minority carrier injection (e.g., by illumination) is not required. Degradation in the surface passivation quality of the poly-Si on oxide layer-corresponding to an increase of the saturation current density J0 by up to a factor of five-causes the degradation of the effective lifetime. Interestingly, the surface passivation fully regenerates under prolonged annealing and finally improves even beyond the initial state. Both the extent of the lifetime degradation and the change in J0 depend on the postprocessing treatment temperature which we varied between 80 and 400 °C. Our results indicate that two different processes are responsible for the degradation and the regeneration. Reference samples which did not receive an RTA treatment show no degradation of the surface passivation quality. The RTA treatment applied therefore triggers the degradation effect. A large improvement of the surface passivation quality under prolonged annealing (e.g., at 400 °C) is observed for all samples examined in this study.
KW - Carrier lifetime
KW - degradation
KW - poly-Si
KW - Poly-Si on oxide (POLO)
KW - silicon
KW - surface passivation
UR - http://www.scopus.com/inward/record.url?scp=85080898300&partnerID=8YFLogxK
U2 - 10.1109/JPHOTOV.2020.2964987
DO - 10.1109/JPHOTOV.2020.2964987
M3 - Article
AN - SCOPUS:85080898300
VL - 10
SP - 423
EP - 430
JO - IEEE journal of photovoltaics
JF - IEEE journal of photovoltaics
SN - 2156-3381
IS - 2
M1 - 8964568
ER -