Rectification and stability of a single molecular diode with controlled orientation

Abstract

In the molecular electronics field it is highly desirable to engineer the structure of molecules to achieve specific functions. In particular, diode (or rectification) behaviour in single molecules is an attractive device function. Here we study charge transport through symmetric tetraphenyl and non-symmetric diblock dipyrimidinyldiphenyl molecules covalently bound to two electrodes. The orientation of the diblock is controlled through a selective deprotection strategy, and a method in which the electrode-electrode distance is modulated unambiguously determines the current-voltage characteristics of the single-molecule device. The diblock molecule exhibits pronounced rectification behaviour compared with its homologous symmetric block, with current flowing from the dipyrimidinyl to the diphenyl moieties. This behaviour is interpreted in terms of localization of the wave function of the hole ground state at one end of the diblock under the applied field. At large forward current, the molecular diode becomes unstable and quantum point contacts between the electrodes form.

Gate-controlled electron transport in coronenes as a bottom-up approach towards graphene transistors

“…We studied the gate eff ect of individual HBC molecules using the following procedures 14 . First, we moved the STM tip close to the substrate covered with a dilute layer of HBC molecules until the tunnelling current between the tip and the substrate reached a preset value.…”

Single-Molecule Analysis Methods Using Nanogap Electrodes and Their Application to DNA Sequencing Technologies

“…SMJs are components of molecular devices, and the development of switch elements, which are generally typified by transistors 87 or diodes, 88 is the main aim of research into molecular devices. 58,89 The low reproducibility of molecular device characteristics is a key issue hindering their development; furthermore, this issue makes it difficult to study the operating principles of these devices.…”

Molecular Tips for Scanning Tunneling Microscopy: Intermolecular Electron Tunneling for Single-molecule Recognition and Electronics

“…In molecular electronics, individual molecules or a small group of molecules are utilized as electronic components, such as wires, 6,7 diodes, [8][9][10] switches, 11,12 and transistors, 13,14 to perform certain electronic functions. 15 Therefore, the most fundamental question in this field is what is the electronic conductance of a junction composed of a single (or a few) molecule(s).…”

“…These studies have been motivated by increasing interest in molecular electronics, which utilizes an individual molecule or a small group of molecules as an electronic component to perform certain functions. A large number of molecules with unique electronic functions, e.g., wires, 6,7 diodes, [8][9][10] switches, 11,12 and transistors, 13,14 have been reported. 15 We have developed molecular tips for STM.…”