Thermally stimulated current studies of charge transport in a σ-conjugated polymer

Thermally stimulated current (TSC) measurements on the σ-conjugated polymer, polymethylphenylsilane (PMPS), are shown to be applicable to the study of hopping transport in this hole-conducting medium. The well-defined hopping peak is dependent both on electric field and heating rate, with the peak temperature occurring between 100 and 150 K. The corresponding activation energies range from 0.2 eV at 30 V/μm to 0.3 eV at 5 V/μ, in agreement with time of flight measurements. A secondary peak at ≈ 180 K attributed to surface trap states was observed only after high exposure doses. These traps had an activation energy of ≈ 0.5 eV and were distinguished from the direct hopping contribution to the current. © 1989.