Air-stable Cd_(0.23)Zn_(0.77)Te nanostructure thin films

摘要

Air-stable CdZnTe nanostructure thin films were synthesized by inert gas condensation technique under constant preparation conditions of Argon gas flow, deposition rate and substrate temperature 300 K. The CdZnTe nanostructure thin films were deposited on freshly cleaned glass substrates. The film thickness has been raised from 20 to 70 nm. The films exhibited nanocrystalline single phase cubic structure as indicated by grazing incident in-plane X-ray diffraction patterns and ensured by HRTEM diffraction patterns. The average particle size of examined films was increased from 5.6 to 10.6 nm by raising thin film thickness as determined from HRTEM images. The average particle size of examined film was measured by HRTEM after 230 day aging and shows a relative stability in the particle size. The optical transmission, reflection and absorption spectra were influenced by the increasing of the particle size P_s. The optical band gap E_g decreased from 3.24 to 3.05 eV as average particle size enlarged from 5.6 to 10.6 nm. Higher values of absorption coefficient spectra and refractive indices have been observed for films of higher particle size. Relative stability of optical properties has been detected for aged film. The d.c. electrical conductivity behavior at different temperatures was tuned by changing the particle size of examined nanocrystalline films. The activation energy values are in the range 0.67-0.77 eV regardless the change in particle size.