Preparation and Some Properties of Metal Organic Chemical Vapour Deposited Al-Doped ZnO Thin Films Using Single Solid Precursors

Abstract

Zinc Oxide (ZnO) and Aluminium doped ZnO (AZO) thin films were deposited on soda lime glass by Metal Organic Chemical Vapour deposition technique (MOCVD), using prepared compound mixtures of Zinc Acetate di-hydrate (Zn(CH 3 COO) 2 •2H 2 O; ZAD) and Aluminium Acetyl-Acetonate (Al(C 5 H 7 0 2) 3 ; AAA) precursors at a temperature of 420˚C. Effects of the varying mole percent concentrations of AAA precursor additives on the Al dopant concentrations in ZnO were systematically studied. The observations were made via investigations carried out on the morphological, optical, electrical and compositional properties of the deposited thin films. The thin films morphology was found to be strongly dependent on the varying concentration of AAA in the precursor mixtures. The average optical transmittance of the thin films in the uv-visible region was over 85% except 5 mol.% Al. While the energy band gaps were found to be in range of 3.27-3.36 eV. There is a blue-shift of the energy band edge observed between 0 and 5 mol.% AAA, which may be due to Burstein-Moss' band gap widening effect and an opposing band gap renormalization effect at 10 mol.% AAA along with an extra band gap stabilization effect (Roth's effect) at 15 mol.% AAA in rather quasi-sinusoidal or anomalous behaviour. The optical transmittance and electrical conductivity of ZnO were enhanced with addition of Al dopants. The RBS confirm the presence of Al, Zn and O, and evidence that Al dopants were successfully incorporated into the ZnO.

Enzyme-Free Molecularly Imprinted and Graphene-Functionalized Photoelectrochemical Sensor Platform for Pollutants

“…Figure b shows the h ν and (α h ν) 2 curves plotted based on the DRS lines. The band gaps ( E g ) of different electrode materials are also calculated using the Tauc plot, which is described as follows: where α, h ν, and A are the absorption coefficient, the photon energy, and a constant, respectively. The index n is related to the characteristics of the transition in a semiconductor, where n = 1/2 for the direct semiconductor.…”

Microstructure and anti-corrosion properties of spray pyrolyzed Ni-doped ZnO thin films for multifunctional surface protection applications

“…The nucleation site number slightly increased as the concentration of Ni 2+ dopant in ZnO. The propensity for substantial and confined nucleation of grains to occur was reported to be because of degenerate ZnO [51,52].…”

Optimal thickness and annealing temperature for enhancement of structural, optical, and photocatalytic properties of ZnO thin films

“…Recently, the development of ZnO thin films and powders in nano-scale has led to more efficient electronic and optoelectronic devices. ZnO thin films can be prepared using various methods, such as magnetron sputtering technique [19], molecular beam epitaxy (MBE) [20], metal organic chemical vapor deposition (MOCVD) [21], pulsed laser deposition (PLD) [22], spray pyrolysis [10,23], ultrasonic spray [24], and sol-gel process [25]. However, the sol-gel spin-coating method is more convenient among the other methods, because of low-cost, accurate compositional control, low crystallization temperature, homogeneity at the molecular level, and easy reproducibility.…”