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This work presents a complete analysis of all Raman active modes of Cu 2 ZnSnS 4 measuring with six different excitation wavelengths from near infrared to ultraviolet. Simultaneous fitting of spectra allowed identification of 18 peaks from device grade layers with composition close to stoichiometry that are attributed to the 27 optical modes theoretically expected for this crystalline structure, including detection of 5 peaks not observed previously, but theoretically predicted. Resonance effects are assumed to explain the observed increase in intensity of weak modes for near infrared and ultraviolet excitations. These results are particularly relevant for experimental discrimination of Raman modes related to secondary phases. V C 2014 AIP Publishing LLC.

This work presents a complete analysis of Raman active modes of Sb2Se3 measured by six different excitation wavelengths from NIR to UV, under different polarization configurations and at low temperature. Simultaneous fitting of spectra allowed the deconvolution and identification of the 28 Raman peaks obtained in monocrystalline Sb2Se3 sample from the 30 modes predicted by the group theory analysis for this crystalline structure. Analysis of the spectra measured under different polarization configurations yielded the preliminary assignment of the peaks symmetry, while the measurements under low temperature resulted in a fine resolution of the peaks in Raman spectra. Additionally, evaluation of the spectra of the most probable secondary phases under different excitation wavelengths allowed to define the most appropriate measurement conditions for experimental discrimination of their Raman peaks in the spectra of Sb2Se3 based thin films solar cells. The combination of different wavelength allows a non-destructive methodology for high sensitivity detection of main secondary phases of the Sb2Se3.

In this work annealing and growth of CuInS 2 thin films is investigated with quasireal-time in situ Raman spectroscopy. During the annealing a shift of the Raman A 1 mode towards lower wave numbers with increasing temperature is observed. A linear temperature dependence of the phonon branch of Ϫ2 cm Ϫ1 /100 K is evaluated. The investigation of the growth process ͑sulfurization of metallic precursors͒ with high surface sensitivity reveals the occurrence of phases which are not detected with bulk sensitive methods. This allows a detailed insight in the formation of the CuInS 2 phases. Independent from stoichiometry and doping of the starting precursors the CuAu ordering of CuInS 2 initially forms as the dominating ordering. The transformation of the CuAu ordering into the chalcopyrite one is, in contrast, strongly dependent on the precursor composition and requires high temperatures.

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The potential of Raman microspectroscopy as a powerful tool in characterizing solids will be demonstrated here with several applications on semiconductors and thin films. The method not only permits the identification of different localized microscopic regions, with a high spatial resolution and with no sample preparation, but also provides several basic information on the microstructure of solids.

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