Charge Transport in TNF: PVK and TNF:Polyester Films and in Liquid, Amorphous and Crystalline TNF

Abstract

Charge transport of excess photoinjected carriers has been studied in a number of materials containing 2, 4, 7 trinitro-9-fluorenone (TNF). Initially measurements were made on charge transfer complexes of TNF with poly-N-vinylcarbazole (PVK). The effect on carrier mobilities of systematic variations of material composition was used to investigate the details of the microscopic transport mechanisms.¹ Similar studies have now been made on the somewhat simpler system in which TNF is dispersed in a polyester matrix. This system has the advantage that no charge transfer complexing occurs and also much higher TNF concentration samples can be prepared. The studies of these polymer systems showed that electron transport is due to intermolecular hopping through TNF states. We have recently extended this study of electron transport in TNF to examine the effects of structure on mobility in the pure TNF system. Drift mobility measurements have been made on liquid, amorphous and crystalline states of TNF. This is the first organic material in which mobility has been measured in all three states.