Development of New Hole-Transporting Amorphous Molecular Materials for Organic Electroluminescent Devices and Their Charge-Transport Properties

摘要

New hole-transporting amorphous molecular materials with high glass-transition temperatures for organic electroluminescent have been developed and their charge-transport properties investigated. They comprise 4,4',4"-tris(diphenyl-2-yl-(phenyl)amino) triphenylamine, 4,4',4"-tris(biphenyl-3-yl-(phenyl)amino)triphenylamine, and 4,4,',4"-tris-(biphenyl-4-yl-(3-methylphenyl)amino)triphenylamine, 4,4',4"-tris(9,9-dimethyl-2-fluorenyl(phenyl)amino)triphenylamine, N,N'-di(biphenyl-2-yl)-N,N'-diphenyl-(l,l'-biphenyl)-4,4'-diamine, N,N'-di(diphenyl-3-yl)-N,N'-diphenyl-(l,l'-diphenyl)-4,4'-dimaine, N,N'-di(diphenyl-4-yl)-N,N'-diphenyl-(l,l'-biphenyl)-4,4'-diamine, N,N'-bis(9,9-dimethyl-2-fluorenyl)-N,N'-diphenyl-9,9-dimethylfluorene-2,7-diamine, and N,N,N',N'-tetrakis (9,9-dimethyl-2-fluorenyl)-(l,l'-biphenyl)-4,4'-diamine. Hole drift mobilities of these materials were determined by the time-of-flight method, and the electric field and temperature dependencies of drift mobility were analyzed in terms of the disorder formalism.