Synthesis of niobium pentoxide from bis(cyclopentadienyl) niobium(IV) dichloride using the spin coating process

Abstract

In this research study, the optical, electrical and structural properties of synthesized niobium pentoxide (Nb2O5) thin films using bis(cyclopentadienyl)niobium(IV)dichloride(C10H10Cl2Nb) as the organometallic niobium precursor have been reported. The samples were formed via the sol-gel spin coating deposition process and calcined at varying temperatures to produce Nb2O5 thin films. The fabricated thin films were then subjected to Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray (EDX) spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Ultraviolet-visible spectroscopy and electrical tests. The XRD showed the films to have an orthorhombic structure, while the EDX indicated the presence of niobium oxide in the thin films. The SEM analysis revealed that the films consisted of nanometric spheres, with the FTIR spectroscopy illustrating the formation of an Nb-O-Nb bond. Also, the thin films showed a high absorbance coefficient in the UV region, with 3.61 eV as the lowest optical energy bandgap at 700 °C. The conductivity and resistivity tests confirmed that the synthesized thin films were good semiconductors. The correlation between the different analyses with respect to the annealing temperatures of the Nb2O5 thin films was also discussed.