Band mobility exceeding 10 cm2 V−1 s−1 assessed by field-effect and chemical double doping in semicrystalline polymeric semiconductors

Abstract

The assessment of intrinsic carrier mobility in disordered polymeric semiconductors is critical for improving optoelectronic devices; however, it is currently limited. We examined how to accurately determine intrinsic, band mobility in doped, semicrystalline polymers using the field-effect and chemical double doping. In particular, chemical doping with a strong molecular oxidant effectively shifts the Fermi energy within the valence band, and field-effect modulation of the carrier density at the Fermi energy determines the field-effect mobility. Therefore, a band-like field-effect mobility exceeding 10 cm2 V−1 s−1 with a negative temperature coefficient was demonstrated for uniaxially aligned semicrystalline polymeric semiconductors, which indicates that the band description derived from the semiclassical Boltzmann transport model is applicable even to semicrystalline polymers with finite structural disorders.