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Raman scattering and disorder effect in Cu 2 ZnSnS 4
Author(s) -
Valakh M. Y.,
Kolomys O. F.,
Ponomaryov S. S.,
Yukhymchuk V. O.,
Babichuk I. S.,
IzquierdoRoca V.,
Saucedo E.,
PerezRodriguez A.,
Morante J. R.,
Schorr S.,
Bodnar I. V.
Publication year - 2013
Publication title -
physica status solidi (rrl) – rapid research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.786
H-Index - 68
eISSN - 1862-6270
pISSN - 1862-6254
DOI - 10.1002/pssr.201307073
Subject(s) - kesterite , czts , raman spectroscopy , raman scattering , excitation , crystal (programming language) , crystallography , phase (matter) , bar (unit) , symmetry (geometry) , chemistry , spectral line , solid solution , materials science , condensed matter physics , analytical chemistry (journal) , band gap , optics , physics , metallurgy , organic chemistry , chromatography , quantum mechanics , astronomy , meteorology , computer science , programming language , geometry , mathematics
The Raman spectra of surface regions of bulk Cu 2 ZnSnS 4 (CZTS) samples with different Cu and Zn cation content were obtained and the differences in the spectra are attributed to statistical disorder effects in the cation sublattice. This disorder in the Cu and Zn sublattices may initiate a change of the crystal symmetry from kesterite‐type $({I\bar 4})$ to $({I\bar 42m})$ space group. The investigated CZTS crystals grown at high temperature are characterised by the co‐existence of regions with different composition ratio of Cu/(Zn + Sn) which results in kesterite and disordered kesterite phases. The presence of a disordered phase with ${I\bar 42m}$ symmetry is reflected in the appearance of a dominant broadened A‐symmetry peak at lower frequency than the peak of the main A‐symmetry kesterite mode at 337 cm –1 . We suppose that due to a small energy barrier between these phases the transition from one phase to the other can be stimulated by optical excitation of Cu 2 ZnSnS 4 . The analysis of the Raman spectra measured under different excitation conditions has allowed obtaining first (to our knowledge) experimental evidence of the existence of such optically induced structural transition in CZTS. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)