Nonlinear Optical Properties of Zinc Oxide Thin Films Produced by Pulsed Laser Deposition

Abstract

Abstract In this work, the nonlinear optical properties of Zinc Oxide (ZnO) thin films produced on microscope slide glass substrates at room temperature (RT) using Pulsed Laser Deposition (PLD) method has been presented. PLD system consists of a vacuum chamber (pumped by a turbo molecular pump, backed with a rotary pump), rotating sample and substrate holders, optical thickness measurement system, infrared temperature measurement system and a nanosecond laser system. Previously deposition vacuum chamber evacuated down to ∼10-8 mbar and deposition was taken place about 1.3×10-1 mbar oxygen background gas pressure value. Morphological properties of thin films were obtained by Atomic Force Microscopy (AFM) that shows homogenous and smooth film structure. Thin films crystallinity were investigated by using X-Ray Diffraction (XRD) method and showed that polycrystalline ZnO structure with the largest peak corresponding to (002) orientation but some films contain Zn with (101) orientation . The thicknesses of the films were deduced from reflectance measurement using a fitting software and crosschecked with profilometer and AFM measurements. The thickness of the films ranged between 10 nm and 220 nm. Linear optical properties were obtained by using UV-VIS Spectrometer. Furthermore, we presented the nonlinear optical properties of the ZnO thin films that were obtained by the z-scan method