The Influence of Deposition Time on the Structural, Morphological, Optical and Electrical Properties of ZnO-rGO Nanocomposite Thin Films Grown in a Single Step by USP

Abstract

Thin films of nanocomposite of zinc oxide–reduced graphene oxide (ZnO-rGO) deposited on soda-lime glass substrates were prepared using ultrasonic spray pyrolysis (USP) at 460 °C. The preparation process does not use harsh acids and is environmentally friendly. The deposition period of 2, 3.5 and 5 min resulted in compact, uniform samples with thicknesses of 148, 250 and 365 nm, respectively. After performing structural, morphological, optical and electrical characterization of the prepared nanocomposite, an influence of the deposition time on the physical properties of the obtained films was determined. TEM analyses indicate that the ZnO-rGO nanocomposite presents ZnO nanoparticles anchored on graphene sheets, while XRD, X-ray Photoelectron Spectroscopy (XPS) and Raman results show the presence of a ZnO phase in the ZnO-rGO films. HR-SEM studies showed changes of the ZnO-rGO thin films morphology due to the incorporation of graphene into the ZnO films. Here, the particles of ZnO are similar to small grains of rice and graphene films have the appearance of a little “rose”. As the thickness of the film increases with deposition time, it reduces the structure of resistance of the nanocomposite thin films to 135 Ω. In addition, the optical transmission of the thin films in the visible region resulted affected. Here, we report a simple methodology for the preparation of ZnO-rGO nanocomposite thin films.

Preparation and photocatalytic performances of ZnO nanostructures: Effects of anodization voltage and time

“…In Figure 4A, the XPS spectrum of ZnO gives the characteristic peak intensities of Zn2p, O1s, and C1s with the corresponding binding energies of 1022, 531, and 285 eV, respectively, and compatible with previous works 56,57 . Figure 4B shows the high‐resolution Zn2p spectrum with two remarkable peaks with binding energies of approximately 1022 and 1045 eV, matching to Zn2p 3/2 and Zn2p 1/2 , respectively, and is in agreement with the published studies 58,59 . The O1s spectrum of ZnO is de‐convoluted into two sub‐peaks by fitting with Gaussian function and illustrated in Figure 5C.…”

“…56,57 Figure 4B shows the high-resolution Zn2p spectrum with two remarkable peaks with binding energies of approximately 1022 and 1045 eV, matching to Zn2p 3/2 and Zn2p 1/2 , respectively, and is in agreement with the published studies. 58,59 The O1s spectrum of ZnO is de-convoluted into two sub-peaks by fitting with Gaussian function and illustrated in Figure 5C. The strong peak at 531.1 eV is attributed to lattice oxygen of the wurtzite structure of ZnO, whereas the weak peak at 532.6 eV is assigned to the hydroxyl oxygen on the surface of ZnO or chemisorbed oxygen species (C O, C O).…”

Synthesis, Characterization, and Photocatalytic Performance of ZnO–Graphene Nanocomposites: A Review

“…For powder samples, the bandgap can be estimated from a diffuse reflectance spectrum [61,138]. In this case, the surface-reflected UV-vis radiation is collected as a function of the photon wavelength, and this reflectance spectrum is transformed to the corresponding absorption spectrum by finding the Kubelka−Munk function F(R ∞ ) = K/S, where K and S are the absorption and scattering coefficients, respectively.…”

Investigation of charge transport mechanism in hydrothermally synthesized reduced graphene oxide (rGO) incorporated zinc oxide (ZnO) nanocomposite films

“…Hybrid nanocomposites have been developed and explored for profound applications such as photodetectors, supercapacitors, gas sensors, solar cells. [1,2]. Among the various metal-oxides, zinc oxide (ZnO) is a prominent semi-conductor with a wide range of applications due to its wide-bandgap, large exciton binding energy, abundant availability, non-toxicity, and high photon-absorption [3,4].…”