Oxygen sensing with individual ZnO:Sb Micro-wires: Effects of temperature and light exposure on the sensitivity and stability

Nanostructured ZnO has been widely investigated as a gas sensing
material. Antimony is an important dopant for ZnO that catalyzes
its surface reactivity and thus strengthens its gas sensing
capability. However, there are little to no studies on the gas
sensing of antimony-doped ZnO single wires. We fabricated and
characterized ZnO/ZnO:Sb core/shell micro-wires and demonstrated that
individual wires are sensitive to oxygen gas flow. Temperature and light
illumination strongly affect the oxygen gas sensitivity and stability of
these individual wires. It was found that these micro- and nano-wire
oxygen sensors at 200˚C give the highest response to oxygen, yet a
vanishingly small effect of light and temperature variations. The
underlying physics and the interplay between these effects are discussed
in terms of surface-adsorbed oxygen, oxygen vacancies and hydrogen doping.