Synthesis and structure analysis of aluminum doped zinc oxide powders

Abstract

Hexagonal Al-doped zinc oxide (ZnO) powders with a nominal composition of Zn 1−x Al x O (0≤x≤0.028) were synthesized by the co-precipitation method. The contents of the Al element in the samples were measured by the inductively coupled plasma-optical emission spectroscopy (ICP-OES) technique. The structures of the Zn 1−x Al x O (0≤x≤0.028) compounds calcined at 1000 and 1200℃ have been determined using the Rietveld full-profile analysis method. Rietveld refinements of the diffraction data indicated that the addition of Al initially has a considerably positive effect on the decreasing of the lattice parameters a and c of Zn 1−x Al x O, but the effect becomes very slight and even negative with the further increase of the Al content. The solid solubility limit of Al in ZnO (mole fraction y) is 2.2l%, resulting in Zn 0.978 Al 0.22 O. It seems that when the Al content is excessive, Al prefers to form a ZnAl 2 O 4 compound with ZnO, but not to incorporate into the ZnO lattice to occupy the Zn 2+ cites. Two phases, [ZnO] (or Al-doped ZnO) and [ZnAl 2 O 4 ], are obviously segregated in Zn 1−x Al x O while the value of x is larger than 0.024. The UV-Vis absorption spectra show that the Al-doped ZnO exhibits a red-shift in the absorption edge without reduced transmission compared with pure ZnO, which also confirms that Al ions enter the ZnO lattice and form a Zn 1−x Al x O solid solution.Al-doped zinc oxide (ZnO), co-precipitation method, X-ray diffraction, crystal structure

Formation of Aluminum‐Doped Zinc Oxide Nanocrystals via the Benzylamine Route at Low Reaction Kinetics

“…Therefore, the availability of high‐quality nanocrystals with fitted sizes and shapes of crystals is required , . In contrast to gas‐phase and solid‐phase processes or co‐precipitation , solvent‐based liquid‐phase syntheses result in better process control with moderate reaction rates , . This synthesis route provides time‐resolved access to measurement technologies in terms of particle formation analysis, as will be shown in this work.…”

Surface effects on the optical and photocatalytic properties of graphene-like ZnO:Eu3+ nanosheets

“…On one hand, the red emission from Eu 3þ ions will increase step by step; on the other hand, the Vo density will increase in the samples due to a higher valence Eu 3þ ions replace a lower valence Zn 2þ ions. 49 As a result, the green emission will be enhanced as well. Moreover, the same variation tendency for both emissions further confirms their native relationship, i.e., Vo indeed serves as the trapping and energy storage centers for the resonant energy transfer from the ZnO host to the Eu 3þ ions in our case.…”

Increasing the Solubility Limit for Tetrahedral Aluminium in ZnO:Al Nanorods by Variation in Synthesis Parameters

“…The thermodynamic solubility limit of Al in ZnO thin films is in the range of 1-2%. An experimental solubility limit has been estimated under 0.3 at% of Al using X-ray diffraction refinements, whereas NMR analyses lead rather to a limit well below 0.1 at% [17,18]. Furthermore, it is believed that only when the dopants occupy substitutional tetrahedral sites in the ZnO crystal lattice, shallow donor levels are created which allow promotion of free carriers into the conduction band [19][20][21].…”