THE EFFECT OF Cu AND Sn ON SOME PHYSICAL PROPERTIES OF CdS THIN FILMS PREPARED BY SPRAY PYROLYSIS

Abstract

In this investigation, thin films of CdS doped with Cu and Sn were prepared on glass substrate using spray pyrolysis techniques. The X-ray diffraction results obtained that the films are polycrystalline and having many phases depends on the doping type. The optical properties of the prepared films were studied in the range of wavelength (300-800)nm. The analysis of the absorption spectra of these films indicates that the films are of direct energy gape of values in the range (1.3-2.5)eV, depending on the type and concentration of the doping .The measurement of refractive index (n) and extinction coefficient (K) obtained that, they were having a changed values in the VIS region with doping concentration. The electrical properties of the prepared films were also studied, it is found that the films having a two activation energies. For 7mass%Sn E1act equal 0.164eVat the temperature interval (295-325)K and E2act equal 0.861 eV in the temperature range (325-425)K. Whereas at 25 mass%Sn,E1act equal 0.108eVin the range (295-370)K and E2act equal 0.542eV in the range (370-450)K. from Hall experiment found that all thin films which doped by Cu and Sn are given P-type.