Facile fabrication of self-assembled ZnO nanowire network channels and its gate-controlled UV detection

Abstract

We demonstrate a facile way to fabricate an array of gate-controllable UV sensors based on assembled zinc oxide nanowire (ZnO NW) network field-effect transistor (FET). This was realized by combining both molecular surface programmed patterning and selective NW assembly on the polar regions avoiding the nonpolar regions, followed by heat treatment at 300 degrees C to ensure stable contact between NWs. The ZnO NW network FET devices showed typical n-type characteristic with an on-off ratio of 10(5), transconductance around 47 nS, and mobility around 0.175cm(2)V(-1)s(-1). In addition, the devices showed photoresponsive behavior to UV light that can be controlled by the applied gate voltage. The photoresponsivity was found to be linearly proportional to the channel voltage V-ds, showing maximum photoresponsivity at V-ds=7V.