Photoluminescence properties of Al-doped ZnO synthesized via facile sol-gel route

Abstract

Pure and Al-doped ZnO nanoparticles are synthesized by hydrothermal technique. The structural and phase analysis of the prepared powder is attained by X-rays diffraction and concluded that Al doping increases the crystallite size and causes compressive stress formation in the material network. Fourier transforms infrared spectroscopy reveals the formation of the aluminum oxide phase but with a tiny size that XRD cannot detect. The impact of different ratios of Al doping influence on powder morphology is carried out using transmission electron microscopy, and the optical bandgap of all synthesized products with the doping ratio is investigated by UV–visible reflectance. The electronic defects localized in the material band-gap are studied via photoluminescence spectroscopy and inferred that Al doping alters significantly the electronic defects nature present in the band-gap. In this study, the intrinsic oxygen vacancies are removed by replacing Zn when Al atoms are introduced into the material network. • Al-doped zinc oxide and Pure ZnO nanopowder has been successfully prepared by using the sol-gel method. • The effect of Al doping ratio on morphological, optical and structural properties has been investigated. • From XRD analysis we concluded that Al doping increases yields to a little increase of a crystallite size and to a compressive stress formation in the material network. • The Al doping yields causes an optical band-gap broadening because of the electronic concentration enhancement. • Fourier transform Infra-red (FTIR) spectroscopy reveals the formation of aluminium oxide phase but with a very small size that cannot be detected by XRD.