Pulsed laser deposition of Pd/WO3 nanoparticles on Si nanostructure for highly sensitive room-temperature gas sensors

The combination of common semiconductors with porous materials has the potential to augment the splitting of electrons and holes, hence increasing the efficiency of gases-sensitive. This study examines the unique sensitivity shown by Pd/WO3 films that were fabricated via the use of the pulsed laser deposition technique on a substrate composed of porous silicon for the purpose of detecting hydrogen sulphide (H2S) and nitrogen dioxide (NO2) over a wide range of temperatures. Tungsten trioxide films doped with palladium (Pd/WO3) are fabricated using pulsed laser deposition at varying laser pulse energies (600, 800, and 1000 mJ/pulse). The ablation process involves the use of a Q-switched Nd/YAG laser operating at a wavelength of 532 nm. The laser system being examined demonstrates pulse duration of 10 ns and a frequency of 1 Hz when used on a porous silicon n-type Si (100) substrate. The study of Pd/WO3 nanoparticles involves the analysis of their crystal structure, optical properties, and morphology through various analytical methods such as X-ray diffraction, UV-Vis spectroscopy, Raman scattering, photoluminescence spectroscopy, and field-emission scanning electron microscopy. The increase in intensity of the pulse laser results in a heightened sharpness of the peaks detected in the Pd/WO3 thin film, indicating an enhancement in crystallinity. The dimensions of the surface particles have shown a rise, followed by a corresponding augmentation in the energy difference, resulting in a heightened degree of uniformity. The study aimed to examine the influence of Pd on the development kinetics of tungsten trioxide nanoparticles. The findings demonstrated that Pd had the capacity to augment sensitivity, reduce operational temperature, and maintain high sensitivity levels even at room temperature. The Pd/WO3 NPs/porous silicon device fabricated in this work, consisting of a Pd/WO3 nanostructure integrated with porous silicon, has remarkable potential as a high-efficiency gas sensor in several sensing technologies.