Raman characterization of Cu₂ZnSnS₄ nanocrystals: phonon confinement effect and formation of Cu _x S phases.

ABSTRACT: A Raman spectroscopic study of Cu₂ZnSnS₄ (CZTS) nanocrystals (NCs) produced by a "green" synthesis in aqueous solutions is reported. Size-selected CZTS NCs reveal phonon confinement that manifests itself in an upward shift of the main phonon peak by about 3-4 cm^-1 by varying the NC diameter from 3 to 2 nm. A non-monotonous shift and narrowing of the main peak are attributed to the special shape of the phonon dispersion in this material. Moreover, the method of sample preparation, the nature of the supporting substrate and the photoexcitation regime are found to crucially influence the Raman spectra of the CZTS samples. Particularly, the possible oxidation and hydrolysis of CZTS NCs with the concomitant formation of a Cu-S phase are systematically investigat

SUBMITTER: Havryliuk Y 

PROVIDER: S-EPMC9085493 | biostudies-literature | 2018 Aug

REPOSITORIES: biostudies-literature