TTF (Tetrathiofulvalene) and TCNQ (tetracyanochinodimethan) are conjugated organic molecules. However, they formed a “metallic conductive interface”, by a charge transfer (CT) complex. Whereby TCNQ is an acceptor molecule and TTF is a donor molecule. [1] Such charge transfer (CT) complexes possess an increased charge carrier concentration within the TTF@TCNQ nanosheets producing hole and electron carriers, donors and anions with holes, or cations and acceptors with electrons. Therefore, superconductivity have been reported for this system. [2,3]
Cu:TTF and Cu:TCNQ nanosheets have been deposited by in different thicknesses by various methods, e.g. spin-coating, dip-coating or electrodeposition methods. The thicknesses have been performed in the range of 2 nm to 30 nm. Peakforce tunneling AFM measurements can be performed on this systems. This TUNA characterizes ultra-low currents (<1pA) through the thickness of nanosheets, and is of particular importance when electrical characterization of conductivity samples is needed at high lateral resolution. High-resolution current mappings of these nanosheets were enabled as well as the corresponding morphology images. Moreover, The I-V currents in the range from pA to nA of these nanosheets have been detected due to the high sensitivity and accuracy of the Peakforce TUNA mode. The resistances of the (Cu)TTF@TCNQ nanosheets can be calculated by using this currents and then the conductivities were also been obtained accordingly.
These superconductive nanosheets will help to construct novel porous superconductive SURMOF hybrid materials in the near future for various device applications.
Reference
- Tang, Q.; Zhou, Z.; Chen, Z. J. Phys. Chem. C, 2011, 115, 18531–18537.
- Kirtley J. R.; Mannhart, J. Nat. Mater., 2008, 7, 520-521.
- Alves, H.; Molinari, A. S.; Xie, H.; Morpurgo, A. F. Nat. Mater., 2008, 7, 574-580
