Conductive polymer: reticulate doping with charge-transfer complex

Abstract

Additives which can form charge-transfer (CT) complexes enhance the photoconductivity of polymers. In contrast, the dark conductivity of polymers containing this type of additive increases only slightly. Several crystalline CT complexes exhibit high dark conductivity. When introduced into polymer matrix these smuld therefore significantly increase its conductivity provided that the CT complexes are ordered, because their high conductivity is related to the strong interactions between donor and acceptor stacks in the crystal. We describe here a new method of introducing microcrystalline CT complexes into polymers. It consists of growing microcrystals during film casting. The system, poly (bisphenol A carbonate)/(PC) with microcrystals of the CT complex of 7,78,8-tetra-cyanoquinodimethane (TCNQ) with tetrathiotetracene (TTT), reaches the dark conductivity of 3 × 10⁻²Ω⁻¹ cm⁻¹ at room temperature at 1 wt% of the complex. This conductivity is only slightly temperature dependent.