Friday, April 9, 2021
Dr. Mihaela C. Stefan
Department of Chemistry and Biochemistry, Department of Bioengineering
University of Texas at Dallas
Friday, April 9th 2021 at 3:30 PM in Hand 1100
Abstract: The smallest S, N-heteroacene, thieno[3,2-b]pyrrole is a good building block for organic semiconductors due to the high electron density, asymmetry, and easily modifiable NH group. Our group have shown that organic semiconductors from thieno[3,2-b]pyrrole display “nearly-ideal” OFET characteristics without compromising charge carrier mobilities or threshold voltages. We have varied the structure and topology to investigate the relatively under-explored banana shape thieno[3,2-b]pyrrole ole semiconductors and the influence of the heteroatom.
Banana shaped donor-acceptor molecules with benzothiadiazole, fluorinated benzothiadiazole acceptors and thieno[3,2-b]pyrrole donor (TP-BT2T-BT and TP-FBT2T-TP) have been reported by our group and the OFET parameters were evaluated in a bottom-gate/bottom-contact (BGBC) OFET architecture. Hole mobility of 0.08 cm2 V-1 s-1 was measured for the molecule (TP-BT2T-BT) with benzothiadiazole as the acceptor. The molecule containing fluorinated benzothiadiazole (TP-FBT2T-BT) showed hole mobility of 1.57×10-3 cm2 V-1 s-1.
Lengthening conjugation by synthesizing conjugated polymers was employed to facilitate the hole transport and to obtain comparatively stable semiconductors. Our group reported the donor-acceptor polymer containing thienopyrrole donor and diketopyrrolopyroole acceptor, P(DPP-TP) and the OFET parameters were evaluated with bottom-gate/top-contact (BGTC) OFET architecture. An increase in hole mobility to 0.12 cm2 V-1 s-1 was observed for the polymer (P(DPP-TP)) as compared to the conjugated small molecules.
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