Influence of Substrate Temperature on Structure and Optical Properties of CdO Thin Films Prepared By Pulsed Laser Deposition


Nanocrystallites of cadmium oxide (CdO) thin films were deposited by pulsed laserdeposition technique on glass substrates using Nd:YAG laser at 532nm wave length.X-ray diffraction (XRD) patterns confirmed the nanocrystalline cubic CdO phaseformation. The intensity of XRD peaks increases with the increase in substratetemperature and better crystallinity takes place at higher temperature. Themorphology of deposited films were characterized by scanning electron microscope(SEM) and atomic force microscope (AFM); with increasing substrate temperature,both the grain size and surface roughness increase .The grain size value (12,18,47nm) and rms roughness values were 63.3, 98.8 and 138.4 nm for thin films depositedat 100 , 200 and 300ºC respectively. UV–Vis spectrophotometric measurementshowed high transparency (nearly 88 % in the wavelength range 500–900 nm) of theCdO thin film with a direct allowed band gap value lying in the range 2.81–3.7eV