ORGANIC EL DEVICE

摘要

Phosphorescent light-emitting layers (51, 52) contain a host for phosphorescence and a phosphorescent dopant for phosphorescence, while a fluorescent light-emitting layer (7) contains a host for fluorescence and a fluorescent dopant for fluorescence. An electron blocking layer (6) blocks electrons injected in the host for fluorescent of the fluorescent light-emitting layer (7) from being injected into the electron blocking layer (6) side from the fluorescent light-emitting layer (7), while allowing holes being injected into the fluorescent light-emitting layer (7) from the phosphorescent light-emitting layers (51, 52). The triplet energy gap Eg_PD of the dopant for phosphorescence of the phosphorescent light-emitting layers (51, 52), the triplet energy gap Eg_EB of the electron blocking layer (6) and the triplet energy gap Eg_FH of the host for fluorescence of the fluorescent light-emitting layer (7) satisfy the following relation (1). Eg_PD < EG_EB = Eg_FH (1)