Patent ID: 10879482

Abstract:
An organic EL device includes a pair of electrodes and an organic compound layer between pair of electrodes. The organic compound layer includes an emitting layer including a first material and a second material. The second material is a fluorescent material. Singlet energy EgS(H) of the first material and singlet energy EgS(D) of the second material satisfy a relationship of the following formula (1). The first material satisfies a relationship of the following formula (2) in terms of a difference ΔST(H) between the singlet energy EgS(H) and an energy gap Eg77K(H) at 77K. EgS(H)>EgS(D)  (1)ΔST(H)=EgS(H)−Eg77K(H)<0.3 (eV)  (2)