Growth of Y3+ doped CeO2 films and their structural, optical, photoluminescence, and gas sensing studies

In the recent past, the development of sensors for harmful gas sensing has been in great demand. Hence, herein, the (0, 1, 2, 3, 4, & 5 wt.%) Yttrium(III)-doped CeO₂ thin films were synthesized using the Nebulizer-assisted spray pyrolysis method for ammonia gas sensing applications. The films exhibited a polycrystalline structure with a cubic phase and a porous morphology, indicating homogeneous crystallization. The surface roughness of the films were increased with Yttrium doping concentration, attributed to the incorporation of Yttrium ions into the Ce sites of CeO₂. UV-Vis-NIR spectroscopy revealed an enhanced absorption in the red region, suggesting the presence of free electrons, which are beneficial for gas sensing. The Yttrium-doped CeO₂ films showed a reduced band gap, thus enhancing their suitability for gas sensing applications. Photoluminescence studies confirmed the presence of free electrons with a sharp blue emission peak at 478 nm, suggesting its application as blue LED. Gas sensing tests demonstrated an increased current value with higher NH₃ concentrations, with the 3% Y-doped CeO₂ thin film showing the best performance. Repeatability tests confirmed a stable gas response over 15 cycles at 250 ppm NH₃, ensuring the reliability and long-term stability of the 3% Yttrium-doped CeO₂ thin film as an effective and durable gas sensing material for industrial applications.

Graphical Abstract