Formation of a Highly‐ordered Thiophene Monolayer on Au(111) via Vapor Phase Deposition

Abstract

STM images and structural model of thiophene self‐assembled monolayers on Au(111).

Thermally Driven Structural Order of Oligo(Ethylene Glycol)-Terminated Alkanethiol Monolayers on Au(111) Prepared by Vapor Deposition

“…The STM images of Figure 2 a,b show that EG2 SAMs vapor-deposited on Au(111) at 298 K for 24 h have a fully disordered phase with many vacancy islands (VIs, dark defects). Such VIs, with a monatomic height of the Au lattice, could be formed through chemisorption of organic molecules containing an active anchoring group, such as sulfur or selenium, onto the gold surface, as reported in many previous papers [ 1 , 2 , 3 , 4 , 5 , 7 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 ]. Therefore, the presence of VIs in EG2 SAMs on Au(111) implies that chemisorbed EG2 monolayers were formed by vapor deposition, as is also the case with EG2 SAMs formed by solution deposition [ 39 ].…”

“…Therefore, it was proposed that the formation of this unique disordered phase is ascribed to the electrostatic repulsions between the EG chains during SAM formation [ 39 ]. In contrast, vapor deposition at an elevated temperature can be very effective for improving the structural quality of SAMs compared to solution deposition [ 7 , 46 , 51 , 52 ]. In this regard, we used STM and CV to characterize EG2 SAMs vapor-deposited on Au(111) for 24 h as a function of deposition temperature.…”

“…STM observations clearly reveal that ambient-pressure vapor deposition is a very simple and useful technique that remarkably enhances the structural order of SAMs on Au(111) derived from alkanethiols, alkyl thiocyanates, and alkyl selenocyanates. This enhancement is due to eliminating possible negative effects that can be induced by solvent-adsorbate interactions during self-assembly in solution [ 7 , 46 , 51 , 52 ]. In spite of numerous studies regarding the effect of deposition temperature on the formation and structure of alkanethiol and alkaneselenol SAMs [ 1 , 4 , 7 , 42 , 43 , 44 , 45 ], there are no molecular-scale STM studies to date regarding temperature-dependent OEG SAM formation on Au(111) by ambient-pressure vapor deposition.…”

Molecular Self‐Assembly of Phenylselenyl Chloride on a Au(111) Surface

“…Self‐assembled monolayers (SAMs) prepared by adsorption of organic molecules onto metals have been the subject of enormous scientific interest because they provide a convenient route for tailoring the surface and physical properties of metals 1–3 . Such properties are controlled simply through appropriate selection of absorbate chemical structure, such as the headgroup and/or terminal functional group 1–18 . This advantageous trait enables SAMs to be utilized in a wide array of applications, such as surface wetting, biosensors, nanolithography, and electronic devices 1–4 .…”

“…[1][2][3] Such properties are controlled simply through appropriate selection of absorbate chemical structure, such as the headgroup and/or terminal functional group. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] This advantageous trait enables SAMs to be utilized in a wide array of applications, such as surface wetting, biosensors, nanolithography, and electronic devices. [1][2][3][4] SAMs derived from organic thiols or disulfides on Au(111) have been extensively studied due to their high structural order and chemical stability resulting from strong chemical interactions between the sulfur headgroup and the gold surface.…”