Benzothiadiazole‐Based Small‐Molecule Semiconductors for Organic Thin‐Film Transistors and Complementary‐like Inverters

Abstract

Abstract New benzothiadiazole derivatives, 4,7‐bis(5‐phenylthiophen‐2‐yl)benzo[ c ][1,2,5]thiadiazole (PT‐BTD) and 4,7‐bis[4‐(thiophen‐2‐yl)phenyl]benzo[ c ][1,2,5]thiadiazole (TP‐BTD), were synthesized and characterized as small‐molecule organic semiconductors for organic thin‐film transistors (OTFTs) and complementary inverters. The thermal, optical, and electrochemical properties of the new compounds were fully characterized. Vacuum‐deposition and solution‐shearing methods were used to fabricate thin films based on these compounds. Thin films based on PT‐BTD exhibited p‐channel characteristics with hole mobilities as high as 0.10 cm 2 V −1 s −1 and current on/off ratios >10 7 for top‐contact/bottom‐gate OTFT devices. With an optimized blending ratio of PT‐BTD and the representative n‐channel semiconductor N , N′ ‐1 H ,1 H ‐perfluorobutyl dicyanoperylenediimide, bulk heterojunction ambipolar transistors were fabricated with balanced hole and electron mobilities of 0.10 and 0.07 cm 2 V −1 s −1 , respectively. Furthermore, a complementary‐like inverter was fabricated using ambipolar thin‐film transistors, which showed a high voltage gain of 84.