Highly soluble small-molecule organic semiconductor with trihexylsilyloxy side chain for high-performance organic field-effect transistors with mobility of up to 3.10 cm2 V−1 s−1

- The record high hole mobility of 3.14 cm2 V−1s−1 in new small molecular organic semiconductor (LGC-D127) is reported.
- Trihexylsilyloxy side chain for organic semiconductors is proposed to provide excellent solubility.
- LGC-D127 OFETs shows high hole mobility (max. 3.06 cm2V−1s−1) from eco-friendly solvent (2-methyltetrahydrofuran).

A donor-acceptor type small molecule organic semiconductor with a trihexylsilyloxy bulky side chain, coded LGC-D127, was synthesized, and its electronic, electrochemical, and electrical properties were investigated for use as the active layer of solution-processable organic field-effect transistors. LGC-D127 consisted of a phenylene-dithiophene moiety with a bulky trihexylsilyloxy side chain as the electron-donating core, diketopyrrolopyrrole as the electron-accepting linker, and octylrhodanine as the electron-accepting end group. In spite of bulky trihexylsilyloxy side chains, LGC-D127 film was highly crystalline. The charge-carrier transport properties of the LGC-D127 was investigated through the fabrication and characterization of field-effect transistor via solution process. LGC-D127 showed significantly high field-effect hole mobility of 3.16 cm2 V−1 s−1 after thermal annealing due to the large crystalline nanostructure and the small grain boundaries. In particular, LGC-D127 had good solubility in the environmentally friendly solvent such as 2-methyltetrahydrofuran due to the bulky trihexylsilyloxy side chain, and its high hole mobility (max. 3.06 cm2 V−1 s−1) was sustained from the LGC-D127 solution in 2-methyltetrahydrofuran.

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