Fig 1.
Au interdigitated electrode (IDE) for electrical measurement fabricated via simple and economical lithography route.
Fabricated IDE array was coated with ZnO thin film, which was further sputtered with different thicknesses of Au.
Fig 2.
Morphological observation of ZnO thin films sputtered with different thicknesses of Au.
Geometrical grain shape analysis and size inspection were conducted to observe the effect of the sputtered thickness of Au. FESEM images of ZnO thin films sputtered with different thicknesses of Au: (a) 0 nm, (b) 10 nm, (c) 20 nm (d) 30 nm, (e) 40 nm and (f) 50 nm.
Fig 3.
TEM images of the ZnO/Au hybrid.
(a) Typical TEM micrograph of 40 nm Au sputtered ZnO. (b) The histogram of 40 nm Au sputtered ZnO showing the particle size distribution. (c) Typical TEM micrograph of 50 nm Au sputtered ZnO. (b) The histogram of 50 nm Au sputtered ZnO showing the particle size distribution. (e) High-resolution TEM image showing the lattice fringes of ZnO and Au. (f) Selected area electron diffraction pattern. ZnO nanowire exhibits a hexagonal spot pattern corresponding to the (100) and (002) planes, and the crystallographic plane of the AuNPs was indexed to (111), corresponding to a hybrid structured Au sputtered ZnO nanocomposite thin film.
Fig 4.
Surface analysis of Au sputtered ZnO.
The surface uniformity and roughness were investigated by AFM. 2D AFM images of the ZnO thin films sputtered with different thicknesses of Au: (a) 0 nm, (b) 10 nm, (c) 20 nm (d) 30 nm, (e) 40 nm and (f) 50 nm.
Fig 5.
Thickness measurements of Au sputtered ZnO thin films with different thicknesses of sputtering.
3D AFM image of Au sputtered ZnO surface sputtered with different thicknesses of Au: (a) 0 nm, (b) 10 nm, (c) 20 nm (d) 30 nm, (e) 40 nm and (f) 50 nm.
Table 1.
Summary of crystallite sizes estimated from the broadening of X-ray diffraction peaks, AFM grain size and RMS value.
Optical band gap and calculated refractive indices of Au-sputtered ZnO thin films at different current densities corresponding to the optical dielectric constant.
Fig 6.
Energy-dispersive X-ray spectra Au sputtered ZnO.
The elemental compositions were investigated by EDX. The EDX images of ZnO thin films sputtered with different thicknesses of Au (a) 0 nm, (b) 10 nm, (c) 20 nm (d) 30 nm, (e) 40 nm and (f) 50 nm.
Fig 7.
Structural characterizations of Au sputtered ZnO.
(a) Structural and grain size analysis of a ZnO thin film matrix. X-ray diffraction analyses of the ZnO thin films sputtered with different thicknesses of Au. (b) Survey scan of the XPS core level spectra for the Au sputtered ZnO nanocomposites. The presence of carbon (C), oxygen (O), zinc (Zn), and gold (Au) were observed in from Au sputtered ZnO thin films without any impurities.
Fig 8.
X-ray photoelectron spectroscopy data showing binding energy.
(a) Zinc, Zn 2p (b) gold, Au 4f (c) gold, Au 4d and (d) oxygen, O1s electrons.
Fig 9.
Optical characterizations of Au sputtered ZnO.
(a) Au-sputtered ZnO thin films to evaluate their performance for UV transmission applications. (b) Band gap observation of Au-sputtered ZnO nanocomposite thin film using a Tauc plot. (c) Photoluminescence spectra of ZnO thin films with different thicknesses of Au sputtered on the ZnO matrix. (d) Schematic illustration of the SPR effect and energy band alignment on the photoluminescence property of Au-sputtered ZnO nanocomposite with different Au thicknesses.
Fig 10.
Electrical characterizations of Au sputtered ZnO.
(a) Impedance spectra, (b) current to voltage (IV) behavior and (c) AC conduction plot of Au-sputtered ZnO thin films with different Au thicknesses.