Ternary CdS1–xSex nanocrystals formed in Cd‐doped As–Se–S films due to photoenhanced diffusion during micro‐Raman measurement

Abstract

AbstractMicro‐Raman spectra of amorphous As–Se–S:Cd films prepared by thermal evaporation on silicon and silicate glass substrates measured at different laser power densities show the formation of CdS1–xSex nanocrystals in the As–Se–S:Cd film under laser beam illumination due to a photoinduced material transfer and photoenhanced diffusion in the laser spot area. The material transfer and the photoenhanced diffusion are caused by a non‐thermal interaction of light with the amorphous As–Se–S:Cd films. The chemical composition of the CdS1–xSex nanocrystals can be determined from the difference of the CdSe‐like and CdS‐like LO phonon wavenumbers in the Raman spectra. The photoluminescence peak energies are in agreement with the CdS1–xSex composition, with the average nanocrystal size being somewhat above the exciton Bohr radius.