Engineering Silicon Oxide Surfaces Using Self‐Assembled Monolayers

Abstract

Although a molecular monolayer is only a few nanometers thick it can completely change the properties of a surface. Molecular monolayers can be readily prepared using the Langmuir-Blodgett methodology or by chemisorption on metal and oxide surfaces. This Review focuses on the use of chemisorbed self-assembled monolayers (SAMs) as a platform for the functionalization of silicon oxide surfaces. The controlled organization of molecules and molecular assemblies on silicon oxide will have a prominent place in "bottom-up" nanofabrication, which could revolutionize fields such as nanoelectronics and biotechnology in the near future. In recent years, self-assembled monolayers on silicon oxide have reached a high level of sophistication and have been combined with various lithographic patterning methods to develop new nanofabrication protocols and biological arrays. Nanoscale control over surface properties is of paramount importance to advance from 2D patterning to 3D fabrication.

Efficient and Air‐Stable Mixed‐Cation Lead Mixed‐Halide Perovskite Solar Cells with n‐Doped Organic Electron Extraction Layers

“…It seems that the incorporation of N-DPBI dopant into C 60 increases the wettability of the C 60 film, which could be due to the increased surface energy of C 60 films in the presence of triphenyl rings in N-DPBI dopant molecules. [35][36][37] In Figure S4 in the Supporting Information we show X-ray diffraction (XRD) patterns of the perovskite films deposited on neat and doped C 60 substrates. All the perovskite films crystallize into a typical tetragonal crystal structure, as reported previously.…”

The molecular level modification of surfaces: from self-assembled monolayers to complex molecular assemblies

“…31 There has been considerable debate on the mechanism of chemisorption. 32 The deposition process is especially complicated; it proceeds through a number of stages, and strongly depends on various parameters, including the solvent and adsorber concentrations, 33 aging of solutions, water content, 34 deposition time and temperature. 35 Initial reports claimed water traces to be essential for the formation of well-packed monolayers.…”

“…In fact, SAMs on SiO 2 have provided molecularly defined platforms for numerous chemical derivatization studies and an extensive tool-box of chemical strategies exists now for chemical transformations at the monolayer surface. 32 …”

Molecules on Si: Electronics with Chemistry

“…For most metals (except the most noble ones, Au and Pt) and compound semiconductors, residual surface oxides are inevitable and fairly unstable, also because of the rich binding chemistry of surface oxides and hydroxides. [37,38] While that same chemistry can be put to good use in molecular electronics (e.g., silanes on SiOx, [39] phosphonates on Al 2 O 3 [40] and GaAs [36] ), below a minimal oxide width the reproducibility and stability of an oxidized surface is poor. An electronically ill-defined oxide also complicates junction modeling.…”