Ambipolar Transport in an Electrochemically Gated Single-Molecule Field-Effect Transistor

作者：Diez Perez Ismael; Li Zhihai; Guo Shaoyin; Madden Christopher; Huang Helin; Che Yanke; Yang Xiaomei; Zang Ling^*; Tao Nongjian

来源：ACS Nano, 2012, 6(8): 7044-7052.

DOI：10.1021/nn302090t

• ambipolar FET
• single-molecule junction
• electrochemical gate
• PTCDI
• STM

Charge transport is studied in single-molecule junctions formed with a 1,7-pyrrolidine-substituted 3,4,9,10-perylenetetracarboxylic diimide (PTCDI) molecular block using an electrochemical gate. Compared to an unsubstituted-PTCDI block, spectroscopic and electrochemical measurements indicate a reduction in the highest occupied (HOMO) - lowest unoccupied (LUMO) molecular orbital energy gap associated with the electron donor character of the substituents. The small HOMO LUMO energy gap allows for switching between electron- and hole-dominated charge transports as a function of gate voltage, thus demonstrating a single-molecule ambipolar field-effect transistor. Both the unsubstituted and substituted molecules display similar n-type behaviors, indicating that they share the same n-type conduction mechanism. However, the substituted-PTCDI block shows a peak in the source drain current vs gate voltage characteristics for the p-type transport, which is attributed to a two-step incoherent transport via the HOMO of the molecule.

• 出版日期2012-8