CHARACTERIZATION OF SPRAY PYROLYZED CDS THIN-FILM DOPED WITH CU

Spray pyrolysed CdS thin film have been converted into p-type by diffu sing Cu atoms for the first time. Copper atoms diffuse into CdS film w hen Cu/CdS bilayer system is annealed. The hot probe and Hall effect s tudies show that the n-type CdS film is converted into p-type. The res istivity of these films is quite high at low Cu concentration while fu rther addition of Cu causes a drastic decrease in the resistivity valu e. The X-ray Diffraction (XRD), X-ray Photonelectron Spectroscopy (XPS ) and optical absorption studies show that Cu merely diffuses into CdS and does not form any chemical reaction with sulphur to form new comp ounds, The Variable Angle Spectroscopic Ellipsometric (VASE) studies c onfirm tile diffusion of copper into CdS and also shows that the Cu at oms diffuse similar to 500 nm into CdS due to annealing at 350 degrees C.