Analysis of one-sun monocrystalline rear-contacted silicon solar cells with efficiencies of 22.1%

Dicker, Jochen; Schumacher, Jürgen; Warta, Wilhelm; Glunz, Stefan

doi:10.1063/1.1446657

Publication type:	Article in scientific journal
Type of review:	Peer review (publication)
Title:	Analysis of one-sun monocrystalline rear-contacted silicon solar cells with efficiencies of 22.1%
Authors:	Dicker, Jochen Schumacher, Jürgen Warta, Wilhelm Glunz, Stefan
DOI:	10.1063/1.1446657
Published in:	Journal of Applied Physics
Volume(Issue):	91
Issue:	7
Page(s):	4335
Issue Date:	2002
Publisher / Ed. Institution:	American Institute of Physics
ISSN:	0021-8979 1089-7550
Language:	English
Subjects:	Carrier lifetime; Semiconductor device models; Surface recombination; Silicon solar cells
Subject (DDC):	621.3: Electrical, communications, control engineering
Abstract:	21.4% efficient rear-contacted cells (RCC) with interdigitated contact grids processed at Fraunhofer ISE on 1.25 Ωcm float-zone silicon are analyzed in detail. The comprehensive description does not only include a two dimensional numerical device simulation, but also a detailed analysis of the optical carrier generation using optical ray tracing and a determination of the losses due to distributed metal resistance and perimeter currents employing a circuit simulation. Bulk- and surface recombination losses are separated combining carrier lifetime and open-circuit voltage measurements with numerical device simulation. The interface surface recombination velocity of the thermally oxidized emitter covering the front surface is deduced to be 1500 cm/s, the bulk diffusion length within the 1.25 Ωcm FZ silicon base is 1200 µm. Despite this excellent bulk diffusion length, the simulations reveal that at maximum power point 80% of the total recombination is due to Shockley Read Hall recombination in the base. A shunt effect at the floating emitter junction at the front side is shown to cause a strongly reduced spectral response for low illumination levels as well as a hump in the dark IV curve. Both effects could be modeled quantitatively assuming the same shunt resistance. Losses due to the distributed metal resistance within the contact grid (including non-generation losses) were determined to cause a fill factor decrease of 1% absolute. Loss currents flowing out of the cell perimeter leads to an additional fill factor loss of 1.5% absolute. The efficiency of the RCC structure was predicted to improve by 3% relative when changing the surface concentration of the front and rear emitter diffusion from 5x10^18 cm^-3 to 1x10^18 cm^-3 with the sheet resistance kept constant. In fact, this modification has lead to an increase in the realized cell efficiency from 21.4% to 22.1%, that is a 3.3% relative improvement.
URI:	https://digitalcollection.zhaw.ch/handle/11475/11580
Fulltext version:	Published version
License (according to publishing contract):	Licence according to publishing contract
Departement:	School of Engineering
Organisational Unit:	Institute of Computational Physics (ICP)
Appears in collections:	Publikationen School of Engineering

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Dicker, J., Schumacher, J., Warta, W., & Glunz, S. (2002). Analysis of one-sun monocrystalline rear-contacted silicon solar cells with efficiencies of 22.1%. Journal of Applied Physics, 91(7), 4335. https://doi.org/10.1063/1.1446657

Dicker, J. et al. (2002) ‘Analysis of one-sun monocrystalline rear-contacted silicon solar cells with efficiencies of 22.1%’, Journal of Applied Physics, 91(7), p. 4335. Available at: https://doi.org/10.1063/1.1446657.

J. Dicker, J. Schumacher, W. Warta, and S. Glunz, “Analysis of one-sun monocrystalline rear-contacted silicon solar cells with efficiencies of 22.1%,” Journal of Applied Physics, vol. 91, no. 7, p. 4335, 2002, doi: 10.1063/1.1446657.

DICKER, Jochen, Jürgen SCHUMACHER, Wilhelm WARTA und Stefan GLUNZ, 2002. Analysis of one-sun monocrystalline rear-contacted silicon solar cells with efficiencies of 22.1%. Journal of Applied Physics. 2002. Bd. 91, Nr. 7, S. 4335. DOI 10.1063/1.1446657

Dicker, Jochen, Jürgen Schumacher, Wilhelm Warta, and Stefan Glunz. 2002. “Analysis of One-Sun Monocrystalline Rear-Contacted Silicon Solar Cells with Efficiencies of 22.1%.” Journal of Applied Physics 91 (7): 4335. https://doi.org/10.1063/1.1446657.

Dicker, Jochen, et al. “Analysis of One-Sun Monocrystalline Rear-Contacted Silicon Solar Cells with Efficiencies of 22.1%.” Journal of Applied Physics, vol. 91, no. 7, 2002, p. 4335, https://doi.org/10.1063/1.1446657.