Common features in the electronic transport behaviour of diverse glassy solids

Abstract

Abstract Key results of recent transport measurements on the silicon backbone polymer, poly(methylphenylsilylene) (PMPS) are reviewed. The hole drift mobility is characterized by a convoluted yet familiar pattern of electric field and temperature dependences. This behaviour in PMPS is remarkably similar to transport behaviour reported in a diverse collection of disordered solids ranging from poly(vinylcarbazole) (PVK) to molecularly doped polymers and even glassy selenium. The latter, however, all share the feature that transport is in part controlled by thermal emission from localized states which act as traps or by field-enhanced thermally assisted electron transfer among such states. The present results thus continue to suggest that a common but incompletely understood mechanism of field-enhanced thermal emission operates to influence transport in a broad class of amorphous solids.