Carbazolyl-substituted triphenyldiamine derivatives as novel photoconductive amorphous molecular materials

Novel branched molecules, N,N'-bis(4-carbazol-9-ylphenyl)-N,N'-diphenyl[1,1'-biphenyl]-4,4'-diamine and N,N'-bis(4-carbazol-9-ylbiphenyl-4'-yl)-N,N'-diphenyl[1,1'-biphenyl]-4,4'-diamine, have been synthesised and found to constitute amorphous molecular materials with glass-transition temperatures (T-g) 69 and 107 degreesC, respectively. The electron photoemission spectra of the amorphous films have been recorded and the ionisation potentials of 5.38-5.46 eV have been established. The hole drift mobility (muh) of the carbazolyl-substituted triaryldiamines was studied by the time-of-flight technique and was found to be in the range of 10(-3) to 10(-4) cm(2)/V s at an applied electric field of 6.4 x 10(5) V/cm. (C) 2004 Elsevier B.V. All rights reserved.