Facile Synthesis of Highly Conductive Vanadium-Doped NiO Film for Transparent Conductive Oxide

Ashique Kotta,Hyung Kee Seo

doi:10.3390/app10165415

Abstract

Metal-oxide-based electrodes play a crucial role in various transparent conductive oxide (TCO) applications. Among the p-type materials, nickel oxide is a promising electrically conductive material due to its good stability, large bandgap, and deep valence band. Here, we display pristine and 3 at.%V-doped NiO synthesized by the solvothermal decomposition method. The properties of both the pristine and 3 at.%V:NiO nanoparticles were characterized by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffractometry (XRD), Raman spectroscopy, ultraviolet–visible spectroscopy (UV–vis), and X-ray photoelectron spectroscopy (XPS). The film properties were characterized by atomic force microscopy (AFM) and a source meter. Our results suggest that incorporation of vanadium into the NiO lattice significantly improves both electrical conductivity and hole extraction. Also, 3 at.%V:NiO exhibits a lower crystalline size when compared to pristine nickel oxide, which maintains the reduction of surface roughness. These results indicate that vanadium is an excellent dopant for NiO.

Highlights

Nickel oxide (NiO) is one of the rare metal oxide semiconductors, exhibiting a wide bandgap of ~3.6 eV [1,2,3]
Another study by Sharma R et al reported that the hole concentration of NiO is enhanced by light Ag doping, and the product was applied in heterojunction diodes (HJDs) [24]
Materials, including Ni (II) acetylacetonate (C10 H14 NiO4 ), oleylamine (C18 H37 N), borane tri-ethylamine [(C2 H5 )3 NBH3 ], and vanadium pentoxide (V2 O5 ), were purchased from Sigma-Aldrich. The properties of both pristine and vanadium-doped NiO (V:NiO) nanoparticles were characterized by field emission scanning electron microscopy (FESEM, Hitachi S-4700, Tokyo, Japan), transmission electron microscopy (TEM, JEM-2010-JEOL, Tokyo, Japan), X-ray diffractometry

Summary

Introduction

Nickel oxide (NiO) is one of the rare metal oxide semiconductors, exhibiting a wide bandgap of ~3.6 eV [1,2,3] It has been used in numerous practical applications, such as organic light-emitting diodes [4], sensors [5], supercapacitors [6], and solar cells [7]. In a study of Agx Nix O film, Jun-Dar et al reported that the Ni+3 /Ni+2 ratio was enhanced by varying concentrations of Ag content [23]. Another study by Sharma R et al reported that the hole concentration of NiO is enhanced by light Ag doping, and the product was applied in heterojunction diodes (HJDs) [24]. The effect of vanadium doping on NiO has not been widely studied

Characterization

Synthesis of Pristine and V-Doped NiO

Results

Itε can

Conclusions