Varying electrical and dielectric properties of Ni:SnO2 films by MWCNTs and GNPs coating

OpenAlex English

Abstract In this research, pure SnO 2 and Ni-doped SnO 2 (Ni:SnO 2 ) nanocomposite films were produced by chemical bath deposition method and the latter were coated with multi-walled carbon nanotubes (Ni:SnO 2 /MWCNTs) or graphene nanoplatelets (Ni:SnO 2 /GNPs) by spin coating. All samples have tetragonal rutile SnO 2 structure with the presence of carbon (002) peak in MWCNTs- or GNPs-coated films. Crystallite size of SnO 2 films decreased remarkably with Ni doping followed by a slight decrease with MWCNTs coating and slight increase with GNPs coating. Scanning electron microscope images manifested a dispersed agglomerative nature of SnO 2 nanoparticles which reduced especially with MWCNTs coating due to the porous surface provided by carbon nanotubes. From the photoluminescence measurements, oxygen defects-related peaks were spotted in the SnO 2 -based structures with different luminescence intensities. The most significant decrease in resistance was observed with the addition of GNPs into Ni-doped SnO 2 nanocomposites compared to the other produced films mainly due to the synergetic effect that promotes excellent charge transfer between surfaces of Ni:SnO 2 and graphene nanosheet. The huge increase in conductivity of GNPs-coated films led to a huge increase in dielectric losses and this followed by a drop down of dielectric constant of the GNPs-coated films.