Patent attributes
An organic electroluminescence device comprising a cathode, an anode and at least one layer comprising a phosphorescent light emitting material and a host material which is sandwiched between the cathode and the anode and further comprising an electron injecting layer which is adhered to the light emitting layer and is capable of transporting electrons, wherein an ionization potential of the host material is 5.9 eV or smaller, and wherein an energy gap of the electron transporting material in the electron injecting layer is smaller than that of the host material in the light emitting layer or wherein a triplet energy of the electron transporting material in the electron injecting layer is smaller than that of the host material in the light emitting layer. It emits phosphorescent light with enhanced efficiency because it comprises a light emitting layer and an electron injecting layer both satisfying specified condition and employs a light emitting layer capable of electron transporting.
