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Title: Electric properties and carrier multiplication in breakdown sites in multi-crystalline silicon solar cells

Abstract

This paper studies the effective electrical size and carrier multiplication of breakdown sites in multi-crystalline silicon solar cells. The local series resistance limits the current of each breakdown site and is thereby linearizing the current-voltage characteristic. This fact allows the estimation of the effective electrical diameters to be as low as 100 nm. Using a laser beam induced current (LBIC) measurement with a high spatial resolution, we find carrier multiplication factors on the order of 30 (Zener-type breakdown) and 100 (avalanche breakdown) as new lower limits. Hence, we prove that also the so-called Zener-type breakdown is followed by avalanche multiplication. We explain that previous measurements of the carrier multiplication using thermography yield results higher than unity, only if the spatial defect density is high enough, and the illumination intensity is lower than what was used for the LBIC method. The individual series resistances of the breakdown sites limit the current through these breakdown sites. Therefore, the measured multiplication factors depend on the applied voltage as well as on the injected photocurrent. Both dependencies are successfully simulated using a series-resistance-limited diode model.

Authors:
; ;  [1];  [1];  [2]
  1. IEK5-Photovoltaics, Forschungszentrum Jülich, Jülich 52425 (Germany)
  2. (Germany)
Publication Date:
OSTI Identifier:
22410264
Resource Type:
Journal Article
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 117; Journal Issue: 20; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0021-8979
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CHARGE CARRIERS; DENSITY; ELECTRIC CONDUCTIVITY; ILLUMINANCE; LASER RADIATION; MULTIPLICATION FACTORS; SILICON SOLAR CELLS; SPATIAL RESOLUTION; THERMOGRAPHY; TOWNSEND DISCHARGE

Citation Formats

Schneemann, Matthias, Carius, Reinhard, Rau, Uwe, Kirchartz, Thomas, E-mail: t.kirchartz@fz-juelich.de, and Faculty of Engineering and CENIDE, University of Duisburg-Essen, Carl-Benz-Str. 199, Duisburg 47057. Electric properties and carrier multiplication in breakdown sites in multi-crystalline silicon solar cells. United States: N. p., 2015. Web. doi:10.1063/1.4921286.
Schneemann, Matthias, Carius, Reinhard, Rau, Uwe, Kirchartz, Thomas, E-mail: t.kirchartz@fz-juelich.de, & Faculty of Engineering and CENIDE, University of Duisburg-Essen, Carl-Benz-Str. 199, Duisburg 47057. Electric properties and carrier multiplication in breakdown sites in multi-crystalline silicon solar cells. United States. doi:10.1063/1.4921286.
Schneemann, Matthias, Carius, Reinhard, Rau, Uwe, Kirchartz, Thomas, E-mail: t.kirchartz@fz-juelich.de, and Faculty of Engineering and CENIDE, University of Duisburg-Essen, Carl-Benz-Str. 199, Duisburg 47057. Thu . "Electric properties and carrier multiplication in breakdown sites in multi-crystalline silicon solar cells". United States. doi:10.1063/1.4921286.
@article{osti_22410264,
title = {Electric properties and carrier multiplication in breakdown sites in multi-crystalline silicon solar cells},
author = {Schneemann, Matthias and Carius, Reinhard and Rau, Uwe and Kirchartz, Thomas, E-mail: t.kirchartz@fz-juelich.de and Faculty of Engineering and CENIDE, University of Duisburg-Essen, Carl-Benz-Str. 199, Duisburg 47057},
abstractNote = {This paper studies the effective electrical size and carrier multiplication of breakdown sites in multi-crystalline silicon solar cells. The local series resistance limits the current of each breakdown site and is thereby linearizing the current-voltage characteristic. This fact allows the estimation of the effective electrical diameters to be as low as 100 nm. Using a laser beam induced current (LBIC) measurement with a high spatial resolution, we find carrier multiplication factors on the order of 30 (Zener-type breakdown) and 100 (avalanche breakdown) as new lower limits. Hence, we prove that also the so-called Zener-type breakdown is followed by avalanche multiplication. We explain that previous measurements of the carrier multiplication using thermography yield results higher than unity, only if the spatial defect density is high enough, and the illumination intensity is lower than what was used for the LBIC method. The individual series resistances of the breakdown sites limit the current through these breakdown sites. Therefore, the measured multiplication factors depend on the applied voltage as well as on the injected photocurrent. Both dependencies are successfully simulated using a series-resistance-limited diode model.},
doi = {10.1063/1.4921286},
journal = {Journal of Applied Physics},
issn = {0021-8979},
number = 20,
volume = 117,
place = {United States},
year = {2015},
month = {5}
}