Charge Mobility in Nonconjugated Dendrons with Charge Transport Functionality in Every Layer

Hole-transporting triarylamine units have been incorporated along the periphery of different generations of a benzyl ether dendrimer, and their field effect mobilities were measured. The charge mobility was found to decrease with generation. We observed that increasing the density of charge transport units in the dendrimer by incorporating triarylamines in every layer of the dendrimer improves the hole mobility in all generations. The mobility increases 4-fold from generation zero to one; the mobility drops and levels off at higher generations. We find that lower generation dendrimers with high density of charge transporting functionalities may prove to be good candidates for applications such as organic photovoltaics. Considering the versatility of dendrons as components of solid state nanoassemblies, the studies here provide useful guidelines for incorporating charge transport functionalities in these branched architectures.