Facile Fabrication of SWCNT/SnO_2 Nanowire Heterojunction Devices on Flexible Polyimide Substrate

摘要

We report on the fabrication and electronic properties of single-walled carbon nanotube (SWCNT)/tin oxide nanowire (SnO_2 NW) heterojunction device arrays on flexible polyimide (PI) substrates. Hetero-NW junctions consisting of crossed SnO_2 NWs and SWCNTs were fabricated by sliding transfer of SnO_2 NWs onto the SWCNT channels on PI substrate. Individual SWCNTs and SnO_2 NWs field effect transistors showed p- and n-type transfer properties with current on/off ratios of 7.0 x 10~5 and 2.7 x 10~6, respectively. The heterojunction diode showed a rectifying behavior with a rectification ratio of higher than 10~3 at ±1 V and the analysis with an equivalent circuit model of serially connected diode and resistor estimated an ideality factor of 1.5 and the resistance of 20 MO. The rectification of AC input signal was clearly demonstrated by fabricating a full-wave bridge circuit of heterojunotions. In addition, the heterojunctions showed a high UV photosensitivity of 104 under reverse bias, suggesting their implicit applications in UV sensors.