Hybrid π-conjugated organosilica materials: semiconductors for the first fully covalent transistor or photovoltaic applications
Résumé
This communication will display the use of novel organosilica materials embedding π-conjugated moieties1 as semiconductors into various applications. For field effect transistors, the π-conjugated core chosen is [1]benzothieno[3,2-b][1]benzothiophene (BTBT)2, first functionalized with hydroxyl groups3 and then modified with hydrolysable and cross-linkable triethoxysilyl moieties. After polycondensation, this compound forms a hybrid material found to be a semiconductor and can be incorporated into field effect transistors. Taking advantage of the sol-gel chemistry involved here, we built Hybrid Field Effect Transistors that are fully cross-linked with covalent bonds. Molecules are cross-linked to each other, covalently bonded to the silicon oxide dielectric and also covalently bonded to the gold electrode thanks to the use of an appropriate surface modifier in between. 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). A solgel processable derivative of fullerene will also be described as promising interlayer for Perovskite n-i-p photovoltaic solar cells4.