New hole-transporting amorphous molecular materials with high glass-transition temperatures (Tgs), 4,4',4"-tris[9,9-dimethyl-2-fluorenyl(phenyl)amino]triphenyl (TFATA) and N,N,N',N'-tetrakis(9,9-dimethyl-2-fluorenyl)-[1,1'-biphenyl]-4,4'-diamin e (FFD), have been developed. TFATA and FFD exhibit hole drift mobilities of 1.7 x 10(-5) and 4.1 x 10(-3) cm(2)V(-1)s(-1), respectively, at 293 K at an electric-field of 1.0 x 10(5) Vcm(-1) in their amorphous glasses. These materials permit the fabrication of thermally stable, high-performance organ ic Light emitting diodes.