Hole transport in binary solid solutions of triphenylamine and bisphenol-<i>A</i>-polycarbonate

Abstract

By means of potential discharge techniques, hole transport has been investigated in binary solid solutions of triphenylamine and bisphenol-A-polycarbonate. Charge was injected from a photoemitting electrode of amorphous selenium. Under space-charge-limited conditions, hole transport can be described by a drift mobility that is linearly dependent upon the electric field. For fields of 105 V/cm, values of the mobility were between 10−7 and 10−5 cm2/V s, depending upon the temperature and concentration. The variation with concentration suggests that hole transport occurs by phonon-assisted hopping between triphenylamine molecules with a charge localization radius of approximately 1.8 Å.