A heterotriangulene polymer for air-stable organic field-effect transistors

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 ∼4.2 × 10−3 cm2 V−1 s−1 and an on/off current ratio of ∼105 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.