Sputter-Grown Pd-Capped CuO Thin Films for a Highly Sensitive and Selective Hydrogen Gas Sensor

In the present work, hydrogen gas sensing properties of palladium-capped copper oxide (Pd/CuO) thin films have been investigated. The Pd/CuO thin films were deposited on glass substrate for different deposition times (10-30 min) using direct current magnetron sputtering. The Pd/CuO thin films were characterized by x-ray diffraction, field emission scanning electron microscopy, atomic force microscopy and x-ray photoelectron spectroscopy for their structural, morphological and compositional properties, respectively. The Pd/CuO thin film sensor deposited for 10 min presents a remarkable sensing performance with fast response/recovery time of 10 s/50 s for hydrogen gas at a concentration of (1000 ppm) and optimum operating temperature of 300 degrees C. The sensor is observed to be highly selective towards hydrogen (H-2) gas compared to the other gases such as carbon monoxide (CO) and ammonia (NH3). The sensor is stable under high humidity conditions (60% RH). The studied Pd/CuO thin film sensor can be used to design a simple and low-cost sensor to detect low concentrations of H-2 gas for use in hydrogen-driven industries.