Gas Sensing and Field Emission Properties of SnO2 & ZnO Nanomaterials

Technological and scientific potentials of high aspect ratio structures of semiconducting oxides are immense and the future of these materials is certainly bright. A thorough understanding of the growth mechanism is a key towards achieving a controlled growth which is of particular significance both for the creation of novel materials as well as for the ultimate device fabrication. In the present work, SnO2 and ZnO based sub-micron structures have been investigated in detail to realize the possible application in gas sensing and field emission devices. The results of the present studies clearly illustrate that the SnO2 matrix can be effectively tailored by doping with elements like Ru, Cu and Th for the selective detection of LPG, H2S and trimethylamine gases, respectively. Interestingly, an ultra-low onset voltage of meager 40 V is obtained for isolated single multipod and one of its arm. The sharp tips of ZnO structures resulted in the onset current density of 2.76 x 107 microA/cm2, which is much greater than the minimum emission current density (1mA/cm2) required to produce the luminance of 300 cd/m2 from VGA-FED.