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Nano-scale compositional analysis of surfaces and interfaces in earth-abundant kesterite solar cells

Published online by Cambridge University Press:  02 November 2016

Kasra Sardashti ,
Dennis Paul ,
Chuck Hitzman ,
John Hammond ,
Richard Haight  and
Andrew C. Kummel
Kasra Sardashti
Affiliation:
Materials Science Program, University of California–San Diego, La Jolla, CA 92093, USA; and Department of Chemistry and Biochemistry, University of California–San Diego, La Jolla, CA 92093, USA
Dennis Paul
Affiliation:
Physical Electronic, Inc., Chanhassen, MN 55317, USA
Chuck Hitzman
Affiliation:
Stanford Nano Shared Facilities, Stanford, CA 94305, USA
John Hammond
Affiliation:
Physical Electronic, Inc., Chanhassen, MN 55317, USA
Richard Haight
Affiliation:
IBM T J Watson Research Center, Yorktown Heights, NY 10598, USA
Andrew C. Kummel*
Affiliation:
Department of Chemistry and Biochemistry, University of California–San Diego, La Jolla, CA 92093, USA
*
a) Address all correspondence to this author. e-mail: [email protected]
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Abstract

Kesterite Cu2ZnSn(S,Se)4 (CZTSSe) absorbers are considered promising alternatives to commercial thin film technologies including CdTe and Cu(In,Ga)Se2 (CIGSe) owing to the earth abundance and non-toxicity of their constituents. However, to be competitive with the existing technologies, the photovoltaic performance of CZTSSe solar cells needs to be improved beyond the current record conversion efficiency of 12.6%. In this study, nanoscale elemental mapping using Auger nanoprobe microscopy (NanoAuger) and nano secondary ion mass spectrometry (NanoSIMS) are used to provide a clear picture of the compositional variations between the grains and grain boundaries in Cu2ZnSn(S,Se)4 kesterite thin films. NanoAuger measurements revealed that the top surfaces of the grains are coated with a Zn-rich (Zn,Sn)Ox layer. While thick oxide layers were observed at the grain boundaries, their chemical compositions were found to be closer to SnOx . NanoSIMS elemental maps confirmed the presence of excess oxygen deeper within the grain boundary grooves, as a result of air annealing of the CZTSSe films.

Keywords

Alalloycasting
Type
Invited Feature Paper
Information
Journal of Materials Research , Volume 31 , Issue 22 , 28 November 2016 , pp. 3473 - 3481
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Copyright
Copyright © Materials Research Society 2016 

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