title: Structure flexibility of the Cu2ZnSnS4 absorber in low-cost photovoltaic cells: from the stoichiometric to the copper-poor compounds.
abstract: Here we present for the very first time a single-crystal investigation of the Cu-poor Zn-rich derivative of Cu(2)ZnSnS(4). Nowadays, this composition is considered as the one that delivers the best photovoltaic performances in the specific domain of Cu(2)ZnSnS(4)-based thin-film solar cells. The existence of this nonstoichiometric phase is definitely demonstrated here in an explicit and unequivocal manner on the basis of powder and single-crystal X-ray diffraction analyses coupled with electron microprobe analyses. Crystals are tetragonal, space group I ̅4, Z = 2, with a = 5.43440(15) Å and c = 10.8382(6) Å for Cu(2)ZnSnS(4) and a = 5.43006(5) Å and c = 10.8222(2) Å for Cu(1.71)Zn(1.18)Sn(0.99)S(4).
authors.affiliation: Institut des Matériaux Jean Rouxel (IMN), Université de Nantes, CNRS, 2 rue de la Houssinière, BP 32229, 44322 Nantes Cedex 03, France.
authors.forename: L
authors.initials: L
authors.lastname: Choubrac
authors.forename: A
authors.initials: A
authors.lastname: Lafond
authors.forename: C
authors.initials: C
authors.lastname: Guillot-Deudon
authors.forename: Y
authors.initials: Y
authors.lastname: Moëlo
authors.forename: S
authors.initials: S
authors.lastname: Jobic