TY - JOUR
T1 - Local atomic structure and analysis of secondary phases in non-stoichiometric Cu2ZnSnS4 using X-ray absorption fine structure spectroscopy
AU - Colina-Ruiz, R. A.
AU - Mustre de León, J.
AU - Lezama-Pacheco, J. S.
AU - Caballero-Briones, F.
AU - Acosta-Alejandro, M.
AU - Espinosa-Faller, F. J.
N1 - Publisher Copyright:
© 2017 Elsevier B.V.
PY - 2017
Y1 - 2017
N2 - The local atomic structure in non-stoichiometric Cu2ZnSnS4 (CZTS) thin films was investigated using X-ray absorption fine structure spectroscopy (XAFS). From the XAFS spectra we infer the presence of disorder in the Cu-Zn plane suggesting that this characteristic might be intrinsic of non-stoichiometric CZTS. This disorder increases with the Cu/(Zn+Sn) ratio. Structural parameters derived from fits to the data show a contraction in the Cu-S bond length and an expansion in the Sn-S bond length, compared to distances obtained from diffraction, for all samples. X-ray absorption near edge spectroscopy (XANES) indicates presence of secondary phases not observed by X-ray diffraction. In Cu-poor samples, ZnS and SnS were identified as secondary phases. The amount of those phases correlates with the Cu deficit and were quantified by a linear combination fit of the XANES of standard materials. This work provides direct evidence of intrinsic disorder in CZTS, which must be considered to generate a realistic atomic structural model, in addition to lattice relaxations and secondary phases.
AB - The local atomic structure in non-stoichiometric Cu2ZnSnS4 (CZTS) thin films was investigated using X-ray absorption fine structure spectroscopy (XAFS). From the XAFS spectra we infer the presence of disorder in the Cu-Zn plane suggesting that this characteristic might be intrinsic of non-stoichiometric CZTS. This disorder increases with the Cu/(Zn+Sn) ratio. Structural parameters derived from fits to the data show a contraction in the Cu-S bond length and an expansion in the Sn-S bond length, compared to distances obtained from diffraction, for all samples. X-ray absorption near edge spectroscopy (XANES) indicates presence of secondary phases not observed by X-ray diffraction. In Cu-poor samples, ZnS and SnS were identified as secondary phases. The amount of those phases correlates with the Cu deficit and were quantified by a linear combination fit of the XANES of standard materials. This work provides direct evidence of intrinsic disorder in CZTS, which must be considered to generate a realistic atomic structural model, in addition to lattice relaxations and secondary phases.
KW - Crystal structure
KW - CuZnSnS
KW - Disorder
KW - Secondary phases
KW - Thin films
KW - XAFS
UR - http://www.scopus.com/inward/record.url?scp=85018264897&partnerID=8YFLogxK
U2 - 10.1016/j.jallcom.2017.04.191
DO - 10.1016/j.jallcom.2017.04.191
M3 - Artículo
SN - 0925-8388
VL - 714
SP - 381
EP - 389
JO - Journal of Alloys and Compounds
JF - Journal of Alloys and Compounds
ER -