Controllable organic nanofiber network crystal room temperature NO2 sensor

We reported an organic room temperature (RT) NO2 sensor based on zinc phthalocyanine (ZnPc) nanofiber network. Compared with traditional polycrystalline ZnPc film devices, the sensors with ZnPc nanofiber network as the sensitive layer exhibit much better recovery characteristics, which could almost recover without any treatments at room temperature. In ZnPc nanofiber network, ultra-thin ZnPc single-crystal fibers not only improve charge transport but also make the charge exchanging process between NO2 and sensitive materials easier. It shortens the response and recovery time and stabilizes the baseline of devices. In addition, we also optimized the sensors by varying the scale of the ZnPc nanofiber. The device performance is obviously improved when the scale of the ZnPc nanofiber becomes smaller. The device could naturally recover and the baseline achieves zero drift. It is attributed to the expansion of the ratio of surface area-to-volume (A/V). (c) 2013 Elsevier B.V. All rights reserved.