Improved Thin-Film Transistor Performance Through a Melt of Poly(para-phenyleneethynylene)

• Published in: Macromolecular rapid communications. Vol. 35; no. 20; pp. 1770 - 1775
• Main Authors: Schmid, Stefanie, Kast, Anne K., Schröder, Rasmus R., Bunz, Uwe H. F., Melzer, Christian
• Format: Journal Article
• Language: English
• Published: Weinheim Blackwell Publishing Ltd 01.10.2014; Wiley; Wiley Subscription Services, Inc
• Subjects: alkyne; Annealing; Application fields; Applied sciences; conjugated polymer; Electronics; Exact sciences and technology; hole mobility; Melts; poly(para-phenyleneethynylene)s; Polymer industry, paints, wood; Polymethyl methacrylates; R&D; Research & development; Semiconductor devices; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Semiconductors; Technology of polymers; thin film transistor; Thin films; Threshold voltage; Transistors; Voltage threshold; poly(para-phenyleneethynylene)s; Annealing; Electrical properties; Hole mobility; Surface topography; Experimental study; Conjugated polymer; Phenylene derivative polymer; Thermal history; Recrystallization; Thin film transistor; alkyne; thin film transistor; conjugated polymer; hole mobility
• ISSN: 1022-1336; 1521-3927
• DOI: 10.1002/marc.201400203

The performance of polymer field‐effect transistors (PFETs) based on short rigid rod semiconducting poly(2,5‐didodecyloxy‐p‐phenyleneethynylene) (D‐OPPE) is highlighted. The controlled heating and cooling of thin films of D‐OPPE allows for a recrystallization from the melt, boosting the performance of D‐OPPE‐based transistors. The improved film properties induced by controlled annealing lead to a hole field‐effect mobility around 0.014 cm2 V−1 s−1, an on/off ratio of 106, a sub‐threshold swing of 3 V dec−1 and a threshold voltage of −35 V, employing a poly(methyl methacrylate) (PMMA) gate dielectric. Thus, PFETs out of D‐OPPE compete now with spin‐coated, polycrystalline poly(3‐hexylthiophene)‐based PFETs. Tame your temper: poly(para‐phenylene­ethynylene)s are spun cast into thin amorphous films that dramatically increase in order and electrical performance upon careful annealing. Optimized top‐gate/bottom‐contact thin film transistors using the annealed poly(phenyleneethynylene) (PPE) show high (0.014 cm2 V−1 s−1) hole mobilities using this simple but powerful processing method. The recorded mobilities of these simple films are in the range of the best obtained values for polythiophene and painstakingly prepared PPE‐nanowires.