Tunable electronic transport characteristics of surface-architecture-controlled ZnO nanowire field effect transistors.

Hong, Woong-Ki; Sohn, Jung Inn; Hwang, Dae-Kue; Kwon, Soon-Shin; Jo, Gunho; Song, Sunghoon; Kim, Seong-Min; Ko, Hang-Ju et al. · Nano Lett · 2008

basic_science · Level V

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Abstract

Surface-architecture-controlled ZnO nanowires were grown using a vapor transport method on various ZnO buffer film coated c-plane sapphire substrates with or without Au catalysts. The ZnO nanowires that were grown showed two different types of geometric properties: corrugated ZnO nanowires having a relatively smaller diameter and a strong deep-level emission photoluminescence (PL) peak and smooth ZnO nanowires having a relatively larger diameter and a weak deep-level emission PL peak. The surface morphology and size-dependent tunable electronic transport properties of the ZnO nanowires were characterized using a nanowire field effect transistor (FET) device structure. The FETs made from smooth ZnO nanowires with a larger diameter exhibited negative threshold voltages, indicating n-channel depletion-mode behavior, whereas those made from corrugated ZnO nanowires with a smaller diameter had positive threshold voltages, indicating n-channel enhancement-mode behavior.