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Computational Analysis of the Optical and Charge Transport Properties of Ultrasonic Spray Pyrolysis-Grown Zinc Oxide/Graphene Hybrid Structures

Ali, A. A. and Hashim, A. M. (2016) Computational Analysis of the Optical and Charge Transport Properties of Ultrasonic Spray Pyrolysis-Grown Zinc Oxide/Graphene Hybrid Structures. Nanoscale Research Letters, 11 (1). ISSN 1931-7573

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Abstract

We demonstrate a systematic computational analysis of the measured optical and charge transport properties of the spray pyrolysis-grown ZnO nanostructures, i.e. nanosphere clusters (NSCs), nanorods (NRs) and nanowires (NWs) for the first time. The calculated absorbance spectra based on the time-dependent density functional theory (TD-DFT) shows very close similarity with the measured behaviours under UV light. The atomic models and energy level diagrams for the grown nanostructures were developed and discussed to explain the structural defects and band gap. The induced stresses in the lattices of ZnO NSCs that formed during the pyrolysis process seem to cause the narrowing of the gap between the energy levels. ZnO NWs and NRs show homogeneous distribution of the LUMO and HOMO orbitals all over the entire heterostructure. Such distribution contributes to the reduction of the band gap down to 2.8 eV, which has been confirmed to be in a good agreement with the experimental results. ZnO NWs and NRs exhibited better emission behaviours under the UV excitation as compared to ZnO NSCs and thin film as their visible range emissions are strongly quenched. Based on the electrochemical impedance measurement, the electrical models and electrostatic potential maps were developed to calculate the electron lifetime and to explain the mobility or diffusion behaviours in the grown nanostructure, respectively.

Item Type:Article
Uncontrolled Keywords:Computation theory, Computational methods, Density functional theory, Energy gap, Graphene, Molecular orbitals, Nanorods, Nanostructures, Pyrolysis, Transport properties, Zinc, Zinc oxide, Computational analysis, Electrochemical impedance measurements, Electrostatic potential maps, Energy level diagrams, Graphene oxides, Homogeneous distribution, Time dependent density functional theory, Ultrasonic spray pyrolysis, Spray pyrolysis
Subjects:T Technology > T Technology (General)
Divisions:Malaysia-Japan International Institute of Technology
ID Code:71664
Deposited By: Widya Wahid
Deposited On:20 Nov 2017 08:28
Last Modified:20 Nov 2017 08:28

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