Synthesis of CuO Thin Film Incorporated with Nanostructured Nd₂O₃ Deposited by Pulsed Laser Deposition for Ammonia Sensing Applications

This study involved depositing thin films of copper oxide (CuO) and copper oxide films incorporated with neodymium oxide (Nd 2 O 3 ) in various weight ratios using the pulsed laser deposition technique to fabricate an ammonia gas sensor. The characteristics of the developed films were characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and photoluminescence spectroscopy (PL) techniques. The study investigated the impact of incorporating Nd 2 O 3 into the CuO film on its sensing characteristics. The X-ray analysis revealed a polycrystalline structure of CuO with a crystal size of 19 nanometers. Furthermore, incorporating CuO and Nd 2 O 3 formed a mixed phase comprised of both CuO and Nd 2 O 3 . The average crystallite size varied with the Nd 2 O 3 incorporation rate from 19[Formula: see text]nm to 14.7[Formula: see text]nm. With increasing Nd 2 O 3 incorporation ratios, the surface morphology changed from smooth to spherical-like nanostructures, and the average particle sizes varied from 28[Formula: see text]nm to 130[Formula: see text]nm. The PL spectrum analysis results confirmed that the incorporation of Nd 2 O 3 resulted in a change in the peak intensity of the PL spectrum, with a significant increase in the peak associated with oxygen vacancies, contributing to the improvement of the sensor response. The incorporation of Nd 2 O 3 greatly enhanced the sensitivity of the as-deposited CuO film. The sample with 5 wt.% Nd 2 O 3 exhibited the maximum sensitivity, reaching 180% against 79 ppm NH 3 at a working temperature of 50[Formula: see text]C.