An organic electroluminescent device comprises a pair of electrodes, and a
layer structure provided between the pair of electrodes and including a
charge transport layer capable of transporting electrons or holes and an
emission layer comprising a major proportion of an organic material
capable of emitting light on application of a voltage thereto via the pair
of electrodes. The organic material undergoes concentration quenching and
the emission layer has a thickness of 4 nm or below. The emission layer
may be made of an electroluminescent organic material, which has a
fluorescent lifetime shorter than an organic material present in the
charge transport layer.
