Piezotronic effect enhanced detection of flammable/toxic gases by ZnO micro/nanowire sensors

0.1016/j.nanoen.2 lsevier Ltd. All rig thors. : [email protected]. (Z.L. Wang). ted equally to this Abstract Compared with conventional Ohmic-contact nanosensors, Schottky-contact has been introduced as a fundamentally new design for much enhanced sensitivity and improved responsive time of onedimensional nanostructure based sensors. Here we demonstrate ZnO micro/nanowire sensors for hydrogen (H2) and nitrogen dioxide (NO2) detections at room-temperature based on a metal– semiconductor–metal (M–S–M) structure. By utilizing strain-induced piezoelectric polarization charges presented at the vicinity of local interface to modify the band structure at Schottky contact, piezotronic effect has been introduced to gate/modulate the charge carriers transport process across the M–S contact and thus hugely enhance/optimize the performances of H2/NO2 gas sensors. Upon straining, the detection sensitivity and resolution are obviously improved, together with a significant enhancement in output current by 5359% for H2 and 238.8% for NO2 detection. This work provides a promising approach to raise the sensitivity, improve the detection resolution, and generally enhance the performance of gas sensing, making it possible for fabricating room temperature of gas sensor while preserving its sensitivity. & 2015 Elsevier Ltd. All rights reserved.