Controlling Electronic States and Transport Properties at the Level of Single Molecules

Abstract

Since molecular electronics has been rapidly growing as a promising alternative to conventional electronics towards the ultimate miniaturization of electronic devices through the bottom-up strategy, it has become a long-term desire to understand and control the transport properties at the level of single molecules. In this Research News article it is shown that one may modify the electronic states of single molecules and thus control their transport properties through designing and fabrication of functional molecules or manipulating molecules with scanning tunneling microscopy. The rectifying effect of single molecules can be realized by designing a donor-barrier-acceptor architecture of Pyridine-sigma-C(60) molecules to achieve the Aviram-Ratner rectifier and by modifying electronic states through azafullerene C(59)N molecules. The effect of the negative differential resistances can be realized by appropriately matching the molecular orbital symmetries between a cobalt phthalocyanine (CoPc) molecule and a Ni electrode. The electronic states and transport properties of single molecules, such as CoPc and melamine molecules, can be altered through manipulation or modifying molecular structures, leading to functionalized molecular devices.

Rectification inversion in oxygen substituted graphyne–graphene-based heterojunctions

“…Investigations on molecular electronic devices have attracted increasing attention and have uncovered several intriguing phenomena and important properties, such as negative differential resistance (NDR), [1][2][3][4] rectifying behavior, [5][6][7] field-effect characteristics, [8][9][10][11] and electronic switching properties. [12][13][14] Molecular rectifiers, in particular, have been attracting great attention because they are amongst the most important electronic elements in the design of modern logic and memory circuits. Since Aviram and Ratner proposed a molecular rectifier based donor-acceptor (D-A) that could function as a diode, 15 enormous theoretical and experimental efforts have been focused on molecular rectifiers.…”

Progress in the Synthesis and Reaction of Azafullerene

“…随着人们对新型材料的需求, 开发利用氮杂富勒烯 已引起人们的关注. 例如, 氮杂富勒烯和封装在单壁碳 纳米管中的氮杂富勒烯表现出很多有趣的材料性质, 如 分子整流器 [54,55] 和光敏剂 [56] . 另外, 由于氮杂富勒烯具 有很好的给电子性质 [57] 和非线性光学活性 [58～60] , 这为 其进一步的应用提供了基础.…”

Negative differential resistance in molecular devices: the role of molecule-electrode coupling

“…Recently, the field of molecular electronics has attracted much attention [1][2][3], and many interesting physical properties, such as negative differential resistance (NDR) effect, rectification, and amplification, have been found in molecular junctions based on single molecules. The NDR effect, which is characterized by a decreasing current through the junction with an increasing voltage bias, is one of the most prominent, because it is a very useful property in molecular electronic devices such as molecular switch, logic cell and memory [4].…”