Unique Role of Self‐Assembled Monolayers in Carbon Nanomaterial‐Based Field‐Effect Transistors

Abstract

Molecular self-assembly is a promising technology for creating reliable functional films in optoelectronic devices with full control of thickness and even spatial resolution. In particular, rationally designed self-assembled monolayers (SAMs) play an important role in modifying the electrode/semiconductor and semiconductor/dielectric interfaces in field-effect transistors. Carbon nanomaterials, especially single-walled carbon nanotubes and graphene, have attracted intense interest in recent years due to their remarkable physicochemical properties. The combination of the advantages of both SAMs and carbon nanomaterials has been opening up a thriving research field. In this Review article, the unique role of SAMs acting as either active or auxiliary layers in carbon nanomaterials-based field-effect transistors is highlighted for tuning the substrate effect, controlling the carrier type and density in the conducting channel, and even installing new functionalities. The combination of molecular self-assembly and molecular engineering with materials fabrication could incorporate diverse molecular functionalities into electrical nanocircuits, thus speeding the development of nanometer/molecular electronics in the future.

Self-assembly of tetraalkoxydinaphthophenazines in monolayers on HOPG by scanning tunneling microscopy

“…In addition to strictly defined conditions of thermodynamical nature such as their reduction and oxidation potentials [7,8], the organic semiconductors suitable for the applications in highly performing devices should meet several requirements concerning their capability of forming ordered supramolecular structures in thin films and monolayers, possibly via self-assembly [9][10][11][12][13][14][15][16][17]. Thus self-assembly of conjugated molecules is one of the crucial factors which influence or even determine the electrical transport properties in organic semiconductors.…”

Diketopyrrolopyrrole‐Based Semiconducting Polymer with Both Hydrophobic Alkyl and Hydrophilic Tetraethylene Glycol Chains for Monolayer Transistor and Sensing Application

“…This agrees with previous reports that the semiconducting performance in FETs is primarily dominated by the first few layers near the dielectric layer. [10][11][12][13][14][15] Adv. Electron.…”

“…[10][11][12][13][14][15] Moreover, downscaling the film thickness to a single molecular layer is of technological interest for the realization of bottomup electronic devices. [16][17][18] In particular, monolayer organic FETs (OFETs) are beneficial for sensing applications as the binding of the respective analytes with the semiconducting monolayer is expected to affect the charge transporting.…”

Supramolecular organization of bi- and terthiophene disubstituted diketopyrrolopyrrole, donor–acceptor–donor semiconducting derivatives

“…In the majority of organic electronics applications capability of self-assembling of molecular semiconductors is of crucial importance because it determines the electrical transport properties in thin active layers and especially at the dielectric/semiconductor interface in such devices as OFETs [10][11][12][13][14]. Scanning tunneling microscopy (STM) is very well suited for the investigations of the self-assembly phenomena, provided that monolayers of the studied compounds can be obtained on appropriate substrates such as gold single crystals or HOPG, assuring images at molecular resolution, for example [15][16][17][18][19][20][21].…”