Study of the Self-Assembling of n-Octylphosphonic Acid Layers on Aluminum Oxide

Abstract

The deposition of n-octylphosphonic acid on aluminum oxide was studied. The substrate was pretreated in order to achieve a root-mean-square roughness of <1 nm, a hydroxyl fraction of 30%, and a thickness of approximately 170 nm. It was proven using X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) that, rather than a monolayer, an organic multilayer was formed. The growth mechanism was identified as a Stranski-Krastanov one. It was also shown that the use of AFM, probing the surface topography, is essential for a reliable quantification and interpretation of data obtained with XPS.

Structural changes in vapour-assembled n-octylphosphonic acid monolayer with post-deposition annealing: Correlation with bias-induced transistor instability

“…When such a monolayer is implemented in low-voltage organic thin-film transistors (OTFTs) based on pentacene, the performance of the asfabricated transistors substantially changes with the duration of the desorption/postdeposition annealing of C 8 PA monolayer [8], pointing to the importance of the monolayer microstructure in the charge carrier transport within the transistor. Shorter post-deposition annealing can also result in C 8 PA thickness larger than a monolayer (cca 1.5 monolayers) [8] that is mimicking the results obtained during the solution self-assembly [10]. Consequently, such dry process can be used as a tool for correlating the structural changes in the C 8 PA monolayer with the short-and long-term transistor performance, while eliminating the effect of possible solvent traces.…”

Towards a reliable characterisation of oxide layers on pure aluminium using high energy resolution FE‐AES

“…[6]: approximately 170 nm. After anodizing, the sample was rinsed with MilliQ water and blow-dried with compressed nitrogen prior to the FE-AES analyses.…”

Influence of chain ordering on frictional properties of self-assembled monolayers (SAMs) in nano-lubrication

“…Alkylphosphonic acids are also an important class of SAM molecules because of their ability to assemble on a number of oxide surfaces, such as tantalum oxide, aluminum oxide, silicon oxide, iron oxide, copper oxide, and mica, and to form robust surface films [78][79][80][81][82][83][84][85][86][87][88][89][90][91][92]. Compared to SAMs of fatty acids, alkanethiols, and alkylsilanes, which have been studied extensively, phosphonic acid-based SAMs have not received much attention [84].…”