Determination of charge carrier mobility of hole transporting polytriarylamine-based diodes

Hole transport properties of three different side chain poly(triarylamines) have been determined by means of the analysis of steady-state current–voltage characteristics using co-planar diode structures. The interpretation is based on space-charge limited models with field-dependent mobility. Mobilities between ~ 10− 8 and 10− 6 cm2 V− 1 s− 1 are obtained. The highest mobility is achieved for poly(tetraphenylbenzidine) devices and the lowest for poly(triphenylamine) devices. Electron-rich methoxy substituents increase the mobility of poly(triphenylamine)s. A comparison of the mobility values with those obtained using organic field-effect transistors is also given.