Scientists Create World’s First Molecular Transistor
a, Representative I(V) curves measured at 4.2 K for different values of VG. Inset, the device structure and schematic. S, source; D, drain; G, gate. Scale bar, 100 nm. b, Fowler–Nordheim plots corresponding to the I(V) curves in a, exhibiting the transition from direct to Fowler–Nordheim tunnelling with a clear gate dependence. The plots are offset vertically for clarity. The arrows indicate the boundaries between transport regimes (corresponding to Vtrans). c, Linear scaling of Vtrans in terms of VG. The error bars denote the s.d. of individual measurements for several devices and the solid line represents a linear fit. Inset, the schematic of the energy band for HOMO-mediated hole tunnelling, where eVG,eff describes the actual amount of molecular orbital shift produced by gating. d, Two-dimensional colour map of dln(I/V2)/d(1/V) (from Fowler–Nordheim plots). Energy-band diagrams corresponding to four different regions (points A–D) are also shown. FN, Fowler–Nordheim tunnelling; DT, direct tunnelling.
The ultimate in electronic device miniaturization would be the creation of circuit elements consisting of an individual molecule. A single-molecule transistor exploiting the electrostatic modulation of a molecule’s orbital energy is a theoretical possibility. Now Hyunwook Song and colleagues report the successful realization of such a device, a proof of concept that should enhance the practical prospects for molecularly engineered electronics
View of James Kushmerick, National Institute of Standards and Technology
Transistors have been made from single molecules, where the flow of electrons is controlled by modulating the energy of the molecular orbitals. Insight from such systems could aid the development of future electronic devices.
Transistors, the fundamental elements of integrated circuits, control the flow of current between two electrodes (the source and drain electrodes) by modifying the voltage applied at a third electrode (the gate electrode). As manufacturers compete to produce ever smaller devices, one logical limit to circuit miniaturization is transistors whose channels are defined by a single molecule…
