Room-temperature molecular-resolution characterization of self-assembled organic monolayers on epitaxial graphene

Abstract

Graphene, a two-dimensional sheet of carbon atoms, is a promising material for next-generation technology because of its advantageous electronic properties, such as extremely high carrier mobilities. However, chemical functionalization schemes are needed to integrate graphene with the diverse range of materials required for device applications. In this paper, we report self-assembled monolayers of the molecular semiconductor perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) formed on epitaxial graphene grown on the SiC(0001) surface. The molecules possess long-range order with a herringbone arrangement, as shown by ultra-high vacuum scanning tunnelling microscopy at room temperature. The molecular ordering is unperturbed by defects in the epitaxial graphene or atomic steps in the underlying SiC surface. Scanning tunnelling spectra of the PTCDA monolayer show distinct features that are not observed on pristine graphene. The demonstration of robust, uniform organic functionalization of epitaxial graphene presents opportunities for graphene-based molecular electronics and sensors.

Sensing at the Surface of Graphene Field‐Effect Transistors

“…[12] The broad sensing potential of graphene can only be unlocked by the introduction of sensitizer (bio)molecules and structures, e.g. various inorganic groups, [23][24][25][81][82][83][84][85][86][87][88][89][90] organic or organometallic molecules, [37,[91][92][93][94][95][96] DNAs, [97][98][99][100][101] proteins, [102] peptides, [30,31,103,104] nanoparticles, [105,106,107] and 2D heterostructure. [51,52,61,108] These molecules are able to respond chemically or physically to their nearby environment, whose responses could then be transduced into an appreciable change in the conductivity of the carbon-based honeycomb scaffold.…”

“…3f shows a scanning tunneling microscopy (STM) image of well-ordered aromatic perylene-3,4,9,10-tetracarboxylic-3,4,9,10-dianhydride (PTCDA) molecules on graphene (as indicated by the a and b vectors), where π-π interaction are the driving force of the self-assembly. [92] The perylene-based monolayer is stable and robust even when exposed to ambient conditions. π-π or hydrophobic interactions between aromatic surface and nucleic acid moieties can also facilitate the decoration of graphene surface with single-stranded DNA (ssDNA) as shown in Fig.…”

Nucleation and growth of thin films of rod-like conjugated molecules

“…Graphene [154,155] can be used as a transparent, flexible and highly conductive electrode for organic electronic applications [156,157]. The combination of optical active films of flat lying molecules on a transparent electrode materials is a promising route to high efficiency OLEDs.…”

Localized intermolecular electronic coupling in two-dimensional self-assembled 3,4,9,10-perylenetetracarboxylic diimide nanoarchitectures

“…[1][2][3][4][5][6][7][8][9][10] Perylene derivatives sublimated under vacuum have the ability to self-assemble on at metal surfaces and to form two-dimensional hydrogen-bonded nanoarchitectures. [11][12][13][14][15][16][17] These molecules can also form multicomponent organic structures when mixed with complementary building blocks. [18][19][20][21][22] Perylene derivatives are thus very attractive to fabricate new devices as new organic at-heterojunction solar cells for example.…”