Schmoltner, K.; Schlütter, F.; Kivala, M.; Baumgarten, M.; Winkler, S.; Trattnig, R.; Koch, N.; Klug, A.; List, E.J.W.; Müllen, K.: A heterotriangulene polymer for air-stable organic field-effect transistors. Polymer Chemistry 4 (2013), p. 5337-5344
We report on a novel air-stable p-type heterotriangulene polymer (PTA) for large-area organic field-effect transistor (OFET) applications. The newly synthesized amorphous organic semiconductor was characterized concerning morphological, optical, electrical and interface related properties and revealed a saturation mobility of similar to 4.2 x 10(-3) cm(2) V-1 s(-1) and an on/off current ratio of similar to 10(5) in bottom-gate/bottom-contact (BG/BC) OFETs. The influence of several interface modifications was investigated in order to optimize the device performance. PTA FETs exhibited excellent air stability over several months and a superior performance compared to the widely used poly(3-hexylthiophene)-based OFETs. Moreover, we show that hydrochloric acid in chloroform leads to protonation of the nitrogen atoms on the PTA polymer, resulting in a significant change of the electrical characteristics of OFETs.