Long term ageing changes in structure and morphology of nanocrystalline ZnxCd1−xSe thin films

Abstract

Long term morphological and structural changes of ZnxCd1-xSe (x=0.4, 0.6 and 0.8) thin films, obtained by solid state alloying of consecutively deposited submonolayers of ZnSe and CdSe, were investigated by means of Atomic Force Microscopy (AFM) and X-ray diffraction (XRD). The XRD investigations show typical solid solution patterns without any decomposition. A relaxation of the lattice is observed through the years, showing tendency towards thermodynamic equilibrium. A. non-uniform strain is observed for x= 0.4 and 0.8, which is proven by the AFM measurements to be due to structural defects. 2D fast Fourrier transform patterns are derived from the AFM images and grain structure evolution and various morphological changes occurring in the films with time are observed and discussed.