Gas Sensing Mechanism and Characterization of Mixed Metal Oxide Thin Films with Different Dopants using Low Cost Chemical Spray Pyrolysis Technique
Gas sensing behavior and mechanism of bare metal oxide thin films SnO¬2, NiO and mixed metal oxide with different dopants (Nickel doped SnO2, Aluminium doped SnO¬2, Cobalt doped SnO2 and Zinc doped SnO2) thin films are fabricated by using chemical spray pyrolysis (CSP) method. Sensing mechanism of these films is investigated by using H2S gas. XRD pattern reveals the polycrystalline nature of the films. The surface morphology is studied by scanning electron microscopy (SEM). The gas sensing mechanism and behavior of these films are studied by using H2S gas. The various dopants of different concentrations were mixed with composite metal oxide thin films, shows better sensing performance. Doping concentrations influence the sensitivity and selectivity of thin films. H2S gas shows reducing behavior for n-type of semiconductor and oxidizing behavior for p-type semiconductor.
Keywords - SnO2, NiO, Mixed Metal Oxides, Dopants, Gas Sensing, Spray Pyrolysis, XRD, SEM