Extremely high oxygen sensing of individual ZnSnO3 nanowires arising from grain boundary barrier modulation

Extremely high oxygen sensing is realized from individual ZnSnO3 nanowires with abundant grain boundaries. The current across one single ZnSnO3 nanowire increases by about six orders of magnitude, from 1.20×10−7to3.78×10−1μA, as the oxygen pressure decreases from 3.7×104to1.0×10−4Pa. Such a drastic sensing is ascribed to grain boundary barrier modulation. This interpretation is confirmed by the sensing experiments under UV illumination. The results demonstrate a promising approach to realize miniaturized and highly sensitive oxygen sensors.