Growth of Nb2O5 film using hydrothermal method: effect of Nb concentration on physical properties

Highly oriented niobium pentoxide Nb 2 O 5 nanoflake-like morphology films were deposited at a certain metal of 2.5 mg ml −1 . Different niobium concentrations of 1.5, 2.5, and 3.5 mg ml −1 were used and reacted with water at a temperature of 150 °C for 72 h as a deposition time. The morphology of the deposited films was studied using a field emission scanning electron microscope (FE-SEM). The crystallographic phases and optical absorption of the deposited films were studied using x-ray diffraction (XRD) and UV–Vis spectroscopy, respectively. XRD results showed that the deposited films were crystalline in nature and highly oriented along the (−402) plane. The crystallite size of the film increased with niobium concentration. Lattice strain and dislocation density were estimated as functions of the Nb concentration. The optical band gap of the nanostructured Nb 2 O 5 was in the range of 3.3–2.9 eV at room temperature depending on the Nb concentration.