Impact of Al doping on microstructure and optical characteristics of tetrapod-like zinc oxide whiskers

Al-doped tetrapod-like zinc oxide whiskers with different Al dopant concentration (0.3∼1.0 mol%) were prepared by solid state reaction method using T-ZnOw and AlCl3 powder as raw materials. X-ray diffraction and SEM microscopy were applied to characterize the structure and surface morphology of the T-ZnOw. The shift of diffraction peaks of ZnO towards high angle indicated the increase of Al-doping concentration. The ZnO whiskers with 0.5 mol% Al doping concentration exhibit good photoluminescence properties with a large PL intensity ratio value (24) and a narrow FWHM value (15 nm). The improvement photoluminescence properties are attributed to the doping of Al element in the ZnO lattice. It is thought that the visible emission with the wavelength of 517 nm is attributed to the electronics transition from Al atoms to Zn vacancy level.