Electron Trapping in N, N'-bis(1,2-dimethylpropyl)-1,4,5,8-naphthalenetetracarboxylic Diimide Doped Poly(styrene)

Electron mobilities have been measured in N,N'-bis(1,2-dimethylpropyl)-1,4,5,8-naphthalenetetracarboxylic diimide doped poly(styrene) containing a series of acceptor traps: 4-(cyanocarboethoxymethylidene)-2-methyl-1,4-naphthoquinone (MNQ), 3,5-dimethyl-3',5'-diisopropyl-4,4'-diphenoquinone (DPQ), 4H-1,1-dioxo-2,6-di-tert-butyl-4-(dicyanomethylidene)thiopyran (TBS), N,N'-dicyano-2-tert-butyl-9,10-anthraquinonediimine (DCAQ), and 4H-1,1-dioxo-4-dicyanomethylidene-2-p-tolyl-6-phenylthiopyran (PTS). From reduction potential measurements, the trap depths of MNQ, DPQ, TBS, DCAQ, and PTS are 0.19, 0.19, 0.20, 0.35, and 0.40 eV, respectively. The mobilities decrease with increasing trap depth and trap concentration. The results are discussed within the framework of the Hoesterey-Letson formalism and the recent simulations of Wolf and co-workers and Borsenberger and co-workers.