π‐Conjugated Organosilica Semiconductors: Toward Robust Organic Electronics

Abstract

The use of novel organosilica materials embedding π‐conjugated moieties as semiconductor into field‐effect transistors is demonstrated. The chosen π‐conjugated core is a [1]benzothieno[3,2‐b][1]benzothiophene that is modified with hydrolyzable and crosslinkable triethoxysilyl moieties. After polycondensation, this compound forms a hybrid material composed of charge transport pathways as well as insulating sublayers made of silicon oxide (SiOx). The hybrid material behaves as a semiconductor and is subsequently integrated as active layer into field‐effect transistors. These precursors show J‐type aggregation that evolves toward H‐type aggregates during the sol–gel process, which improve charge transport. Taking advantage of the sol–gel chemistry involved here, hybrid field‐effect transistors that are fully crosslinked with covalent bonds are built. Molecules are crosslinked to each other, covalently bonded to the silicon oxide dielectric, and also covalently bonded to the gold electrodes, thanks to the use of an appropriate additional interfacial monolayer. This is the first report of fully covalent transistors. Those devices with modest mobilities show impressive resilience against polar, aliphatic, and aromatics solvents even under sonication. This study opens the route toward a new class of hybrid materials to create highly robust electronic applications.