Energy-Level Engineering in Self-Contact Organic Transistors Prepared by Inkjet Printing

Organic field-effect transistors with chemically doped source/drain electrodes are fabricated by selectively transforming the active layer to the conducting material, organic charge-transfer (CT) complex, using inkjet printing. The formation of the CT complex is investigated by X-ray diffraction and Raman spectroscopy, and the resulting CT complex is conducting enough to realize satisfactory transistor performance. The solvent of the ink is a key factor to achieve the optimal chemical doping to form a well-ordered CT complex. In such a manner, we can obtain semiconductor-specific electrodes that significantly reduce the schottky barrier at the electrode/semiconductor interface, because ideal energy-level engineering is automatically attained between the same type of molecules.