Structural and optical investigation of Al doped ZnO nanoparticles synthesized by Sol-gel process

Abstract

Background/Objectives: Nanoparticles possess unique properties due large surface to volume ratio and quantum confinement effect. ZnO is suitable for laser diodes, LEDs and Photodetectors due to wide direct band gap, high melting point, high thermal conductivity etc. Methods/Statistical analysis: Pure Zinc oxide and Al doped ZnO Nanopowders are fabricated by Sol-gel method. Influence of Al doping on structural and optical properties of Nanopowders were analyzed by X Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), UVVisible optical absorption (UV-Vis) and Photoluminescence (PL) Characterizations. Sol-gel method is preferred due to its simplicity, low Cost and Environment friendly. Structural properties including crystalline size, Lattice strain were obtained from XRD. Morphology of Nanopowders confirmed from SEM micrographs observed at different magnifications. Presence of functional groups obtained from FTIR spectra. Band gap is determined from UV-Visible optical absorption spectroscopy. Luminescence emissions were confirmed from PL characterizations. Findings: The average crystalline size of Nanopowders is found to be 36.448 nm and 62.83 nm for pure ZnO and Al doped ZnO nanopowders respectively. The morphology strongly influenced by doping with Aluminum. Structural properties of nanoparticles again proved from FTIR Spectra. The energy band gap value of Nanoparticles obtained is found to be decreased by doping with Al. The increase in the light output intensity could be attributed to increase in the Light transmittance. Application/Improvements: The synthesized Nanopowders can be used in the fabrication of ZnO Nanorods, Nanowires which is an attractive potential application in the Light emitting devices, UV Photodetectors.