Interface-Induced Face-on Orientation of Organic Semiconductors with a Template Layer and Its Application to Vertical-Type Organic Transistors. Issue 9 (10th April 2019) - Yamada, Keitaro
Abstract : Molecular orientation control with a template material, perylene 3, 4, 8, 9-tetracarboxylic dianhydride (PTCDA), was investigated for various π-conjugated crystalline molecules, namely copper phthalocyanine (CuPc), N, N'-Dimethyl-3, 4, 9, 10-perylenedicarboximide (MePTC), pentacene and dinaphtho[2, 3-b:2', 3'-f]thieno[3, 2-b]thiophene (DNTT). The molecular orientation of CuPc and MePTC clearly changed from edge-on to face-on orientation by depositing on PTCDA. The electron mobility of MePTC, which is an n -type organic semiconductor suitable for vertical carrier transport, improved approximately three times owing to face-on molecular orientation. Thin-film X-ray diffraction studies revealed that the molecular packing mode (stacking or herringbone) affects the molecular orientation control. The MePTC film oriented with PTCDA was applied to a vertical-type organic transistor, a metal base organic transistor (MBOT), resulting in higher output current and current gain.