Growth, patterning, and one-dimensional electron -Transport properties of self-assembled Ag-TCNQF₄ organic nanowires

Controllable synthesis approaches for organic nanowires that permit the in situ fabrication of devices will enable future applications in nano-electronics and nano-optoelectronics. Here, the first synthesis of single-crystal silver-tetrafluorotetracyano-p-quinodimethane (Ag-TCNQF₄) nanowires is reported. Ag-TCNQF₄ is a good charge-transfer complex and nanowires of this organic semiconductor material were deterministically synthesized in a facile vapor-solid process on selected regions through the reaction of TCNQF₄ vapor with patterned silver. Use of a growth barrier is shown to control the growth of Ag-TCNQF₄ nanowires to horizontal alignment, permitting the reproducible in situ growth of single Ag-TCNQF₄ nanowire devices and device arrays between prefabricated electrodes. The single-crystal nanowires are predominantly monoclinic in structure with efficient π-stacking of the TCNQF₄ units, leading to a high conductivity along the nanowire. However, the electron-withdrawing fluorine groups on the π-delocalized ring in the TCNQF₄ results in a distinctly different structure compared to that previously reported for Ag-TCNQ nanowires. The temperature- and bias-voltage-dependent electrical transport properties of in situ fabricated Ag-TCNQF₄ organic nanowire devices were investigated and exhibit a power-law behavior characteristic of one-dimensional systems.