Abstract
On the basis of density functional calculations of electronic structure by the Siesta method in the local density approximation, the zone-center vibrational spectra for two crystallographic modifications of Cu2ZnSnSe4 are constructed. The difference of frequencies, between kesterite and stannite phases, of some characteristic modes is discussed. It is suggested to use some of these modes (notably the Zn-related one at 239–254 cm-1) as a vibrational signature of the kesterite structure, e.g., for samples characterization.
Summarize
Summarizing, we provided a first-principle description of zone-center phonons in KS and ST structures of CZTSe, supported by available experimental information. The predicted differences in frequency of some characteristic modes may be, in our opinion, useful for identifying KS or ST phases by means of vibrational spectroscopy