The Effect of Al Doping on Structural, Electrical and Optical Properties of CdSe Films

Abstract

CdSe thin films were deposited on glass substrates by chemical bath deposition technique. The deposited CdSe thin films were annealed by thermal evaporation for (1h) at 250 ˚C. The samples were then coated with a different thicknesses of thin Al films (50, 100, 150, 200) Å by thermal evaporation method which then annealed at (1h,250˚C). The structural, optical, and electrical properties of deposited and doped samples were studied. The X-ray diffraction analysis showed that the films have polycrystalline structure of hexagonal type. From optical properties, the band gap energy of undoped CdSe thin film was 2 eV and it is decreased by increasing of Al doping. Electrical resistivity of the doped films showed a decrease with the increase of the Al concentration. The doped and undoped samples revealed that the conductivity was n-type