Patent ID: 8436343

Claim:
An organic EL device, comprising: an anode; a cathode; and an organic thin-film layer provided between the anode and the cathode, said organic thin-film layer comprising: a fluorescent-emitting layer containing a fluorescent host and a fluorescent dopant; a red phosphorescent-emitting layer containing a red phosphorescent host and a red phosphorescent dopant; and a green phosphorescent-emitting layer containing a green phosphorescent host and a green phosphorescent dopant, wherein the red phosphorescent dopant emits light mainly by receiving transfer of triplet energy from the fluorescent host, and the green phosphorescent dopant emits light mainly by recombination of charges within the green phosphorescent-emitting layer, wherein the triplet energy gap Eg FH of the fluorescent host and the triplet energy gap Eg PH-G of the green phosphorescent host satisfy a relationship of Eg FH <Eg PH-G , the triplet energy gap Eg PH-G of the green phosphorescent host is 2.4 eV or more, and wherein the triplet energy gap Eg FH of the fluorescent host, triplet energy gap Eg PD-R of the red phosphorescent dopant and the triplet energy gap Eg PD-G of the green phosphorescent dopant satisfy a relationship of Eg PD-R <Eg FH <Eg PD-G +0.2 eV.