In situ determination of the energy dependence of the high-frequency mobility in polymers

The high-frequency mobility (μhf) in disordered systems is governed by transport properties on mesoscopic length scales, which makes it a sensitive probe for the amount of local order. Here we present a method to measure the energy dependence of μhf by combining an electrochemically gated transistor with in situ quasioptical measurements in the subterahertz domain. We apply this method to poly([2-methoxy-5-(3′,7′-dimethylocyloxy)]-p-phenylene vinylene) and find a mobility at least as high as 0.1cm2V−1s−1.