Floating Back-Gate Field Effect Transistor Fabricated Using a Single Nanowire of Charge Transfer Complex as a Channel

Metal-organic charge transfer complex (MOCT) material have good application potentials. We report a high carrier mobility in MOCT material Cu:tetracyanoquinodimethane (Cu:TCNQ) single nanowire (NW). A novel floating back gate field effect transistors is fabricated using Cu:TCNQ single NW of diameter ranging from similar to 50 to 100 nm and length similar to 1.0-2.0 mu m as channel material. Floating gate is made of conducting Si (c-Si) electrically isolated from the environment by thermally grown SiO2 (100 nm thickness) all around it, which is an easy and inexpensive approach to reduce leakage current and improve the device performance. The devices can exhibit on/off current ratio of similar to 10(2)-10(4) at room temperature. Mobility of the NW channel as measured in different single NW devices is similar to 4.3 X 10(2) to 1.2 X 10(4) cm(2) V-1 s(-1) which is the best reported mobility in such molecular materials. The observed high mobility has been proposed to arise from pi-pi. stacking of the molecular orbitals of donor-acceptor type CT materials and good crystallinity and also small device size that reduces carrier scattering.