ORGANIC ELECTROLUMINESCENT ELEMENT

摘要

The organic electroluminescent element prevents degradation of phosphorescent luminescent organic metal complexes in a light emitting layer, has a long life, and has superior color stability during continuously drive. The organic electroluminescent element has a blue light emitting layer with a phosphorescent light emitting organometallic complex (A) with a local maximum phosphorescent light emission wavelength on the short wave side of 480 nm or less, a phosphorescent light emitting organometallic complex (B), and a host compound. The content of complex (A) is greater than the content of the complex (B). The complex (A) and the host are such that a single layer made from complex (A) and the host compound, the value for the ratio ((D)/(C)) of the percent of remaining luminescence (C) which UV irradiation with a wavelength of 365 nm and the percent of remaining luminescence (D) with UV irradiation by a HgXe light source is 0.75-0.95.

主权项

1. An organic electroluminescent element comprising an anode, a cathode, and a light-emitting layer disposed between the anode and the cathode, on a substrate, wherein
the light-emitting layer at least includes a blue light emitting sublayer; the blue light-emitting sublayer satisfies Requirement 1 and contains a phosphorescent organic metal complex (A) showing a phosphorescent spectrum having a maximum phosphorescent wavelength of 480 nm or less on the shortest wavelength side, a phosphorescent organic metal complex (B), and a host compound; and the blue light-emitting sublayer contains the phosphorescent organic metal complex (A) in an amount larger than that of the phosphorescent organic metal complex (B), Requirement 1: a blue light-emitting monolayer film composed of the phosphorescent organic metal complex (A) and the host compound formed on a quartz substrate has a ratio ((D))/(C)) within a range of 0.75 to 0.85 of the brightness persistence (D) in a UV irradiation test using a Hg—Xe light source to the brightness persistence (C) in a UV irradiation test using a light source of a 365-nm wavelength, under a same absorbed UV photon energy.