Reliable mobility evaluation of organic field-effect transistors with different contact metals

The reliability of mobility evaluation of organic field-effect transistors (OFETs) is a serious issue because numerous overestimated and underestimated mobilities have been reported recently. A reliable approach to accurately evaluate the OFET mobility is therefore highly desirable. Here, in this letter, two commonly employed methods and the Y function method (YFM) were used to extract the mobilities of indacenodithiophene-co-benzothiadiazole (IDT-BT) OFETs with four different contact metals. The mobilities extracted by the commonly used methods varied greatly with the contact metal and channel length, whereas those extracted by the YFM were very stable and approached the intrinsic mobility of IDT-BT. Our results show that YFM is a precise approach that can be widely used to evaluate the OFET mobility.