Effect of substrate temperature on properties of deposited Nb2O5 thin films prepared by RF sputtering for gas sensing applications

• Published in: Indian journal of physics 2024-11, Vol.98 (12), p.3891-3899
• Main Authors: Alptekin, S., Khudhair, I. A., Sert, E., Khalaf, M. K.
• Format: Article
• Language: English
• Subjects: Astrophysics and Astroparticles; Original Paper; Physics; Physics and Astronomy
• ISSN: 0973-1458; 0974-9845
• DOI: 10.1007/s12648-024-03152-0

In this study, the influence of substrate temperature of the RF (Radio frequency) deposition system under a high vacuum on the characteristics of the deposited niobium oxide (Nb 2 O 5 ) thin films was investigated. The X-Ray diffraction (XRD) measurements showed a polycrystalline orthorhombic structure for the pure Nb 2 O 5 phase. The crystallinity was enhanced and the crystalline size was enlarged with the deposition temperature causing to a reduction in the lattice strain. The surface morphology investigated by scanning electron microscope (FE-SEM) shows the uniformity of the prepared thin films over the entire surface. Increasing the deposition temperature causes an increase in the oxidizing degree. The process might reduce the electron vacancies. The optical properties show that the band edges become sharper with an increase in the substrate temperature. The energy bandgap values increased with the deposition temperature. The response of the prepared gas sensor is highly affected by working temperature, particle size, surface roughness, and oxygen vacancies. The maximum sensitivity appeared at 250 °C working temperature is 118.2 against H 2 S gas for the sample prepared at room temperature (RT) at 160 W RF power.