In this work, Raman spectroscopy and X-ray diffraction were applied together
to evaluate the crystal structure and the phonon modes of photovoltaic grade
Cu 2ZnSn(SxSe1−x)4 thin films, leading to a complete characterization of their
structural and vibrational properties. Vibrational characterization has been
based on Raman scattering measurements performed with different excitation
wavelengths and polarization configurations. Analysis of the experimental
spectra has permitted identification of 19 peaks, which positions are in good
accord with theoretical predictions. Besides, the observation of Cu
2ZnSnS4-like A symmetry peaks related to S vibrations and Cu 2ZnSnSe4-like A
symmetry peaks related to Se vibrations, additional Raman peaks,
characteristic of the solid solution and previously not reported, are
observed, and are attributed to vibrations involving both S and Se anions