Photodegradable self-assembled monolayers bearing polyhedral oligosilsesquioxanes on metal oxides for the patterned deposition of silver nanoparticle ink and organic semiconductor

Abstract

Three surface modifiers consisting of three parts were synthesized to fabricate photo-patternable self-assembled monolayers (SAMs) on inorganic materials for pattern-transformation; the first part is the one that binds to the surface of metal oxides (trialkoxysilane or phosphonic acid with an amino group at the end), the second is an o-nitrobenzyl (ONB) linker that protects the amino group, and the third is a hydrophobic polyhedral oligomeric silsesquioxane (POSS) that is connected to the linker. The immobilized silicon wafer with a silane coupling agent or indium tin oxide with the phosphonic acid became nearly as hydrophobic as the silicon surface-modified with perfluoroalkyl agents. After photoirradiation, the second and third parts (ONB linker with the POSS moiety) were removed and the modified surfaces became hydrophilic owing to the appearance of amino groups. This was confirmed using the contact angle of water and X-ray photoelectron spectroscopy data. Silver nano-ink or 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene was selectively deposited on the photo-irradiated region using a mask.