title: A detrimental reaction at the molybdenum back contact in Cu2ZnSn(S,Se)4 thin-film solar cells.
abstract: Experimental proof is presented for a hitherto undetected solid-state reaction between the solar cell material Cu(2)ZnSn(S,Se)(4) (CZTS(e)) and the standard metallic back contact, molybdenum. Annealing experiments combined with Raman and transmission electron microscopy studies show that this aggressive reaction causes formation of MoS(2) and secondary phases at the CZTS|Mo interface during thermal processing. A reaction scheme is presented and discussed in the context of current state-of-the-art synthesis methods for CZTS(e). It is concluded that alternative back contacts will be important for future improvements in CZTS(e) quality.
authors.affiliation: Ångström Solar Center, Solid State Electronics, Uppsala University, 751 21 Uppsala, Sweden. jonathan.scragg@angstrom.uu.se
authors.forename: Jonathan J
authors.initials: JJ
authors.lastname: Scragg
authors.forename: J Timo
authors.initials: JT
authors.lastname: Wätjen
authors.forename: Marika
authors.initials: M
authors.lastname: Edoff
authors.forename: Tove
authors.initials: T
authors.lastname: Ericson
authors.forename: Tomas
authors.initials: T
authors.lastname: Kubart
authors.forename: Charlotte
authors.initials: C
authors.lastname: Platzer-Björkman