Effect of Excimer-Forming Sites on Carrier Transport Process in Photoconductive Polymers

Abstract

A study of carrier transport properties is reported for “bichromophores” molecularly dispersed in a polycarbonate. The concentration of Excimer-Forming Sites (EFS) can be controlled in dually molecularly doped polymers by adjusting the molar ratio of 1, 3-biscarbazolylpropane (1, 3-BCzP) to 1, 2-trans-biscarbazolylcyclobutane (1, 2-BCzB). The hole drift mobility of 1, 2-BCzB doped polymer which is free from excimer is higher by an order of magnitude than that of poy (N-vinylcarbazole). It greatly dropped by addition of a small amount of 1, 3-BCzP, which makes an intramolecular excimer. Thus EFS control the carrier transport as intrinsic structural traps.