Amar Kamal Mohamedkhair Salih
Synthesis and Modification of Tin Oxide Based Thin Films for Hydrogen Gas Sensing
Date of Degree
The global demand for energy is increasingly attracting the attention of researchers to investigate sources of clean energy. Hydrogen (H2) is considered one of the main sources of such energy. Nevertheless, the explosive nature of hydrogen make it difficult to deal with, particularly if the concentration reaches 4%. Detection of very low concentration of H2 is essential in various applications, especially in the applications of environmental and chemical industries. In this work, a simple and facile strategy has been demonstrated to fabricate highly sensitive and fast response hydrogen gas sensors based on sputtered tin oxide (SnO2) thin films. These films were catalyzed by a very thin layer of noble metals such as silver (Ag), gold (Au), platinum (Pt) and palladium (Pd) as catalysts, followed by heat treatment at different annealing temperature. Structural, morphological, optical, and compositional properties of the fabricated sensors were investigated by different analytical techniques, including X-ray Diffraction (XRD), Atomic Force Microscopy (AFM), field emission scanning electron microscope (FESEM), UV-Vis absorption, and X-ray Photoelectron Spectroscopy (XPS). The gas sensing properties of the modified SnO2 sensors were investigated and compared with pristine SnO2. The dependence of the sensor response to the operating temperature (RT-500°C), H2concentration, annealing temperature and noble metal addition was studied. A plausible mechanism for the observed enhancement in the sensing performance towards H2 is proposed.