Room-temperature ultraviolet emission from an organic light-emitting diode

Ultraviolet emission was obtained from N,N'-diphenyl-N,N'-bis(3-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine. Gallium nitride was used as a hole-blocking layer to contain the holes. A peak emission wavelength of 400 nm was measured. The external quantum efficiency is about 0.35%. (C) 2001 American Institute of Physics.