| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a white organic EL element consisting of a single luminescent layer which, while retaining the chromatic purity of white color, maintains the average density of dopants to realize life improvement, thereby offering an organic EL element which excels in power efficiency. <P>SOLUTION: In a white organic EL element having a plurality of organic layers including a hole transport layer, a luminescent layer and an electron transport layer between an anode and a cathode, the luminescent layer contains three or more kinds of dopants differing in maximum luminescent wavelength. More specifically, assuming a B dopant of 430 to 480 nm in maximum luminescent peak wavelength, a G dopant of 500 to 540 nm and an R dopant of 520 to 560 nm, the luminescent layer contains at least three dopants selected from each of these three categories. The B dopant in the luminescent layer is a phosphorescent dopant, which is a phosphorescent luminescent material whose phosphorescence life is less than 1.4 μsec and whose phosphorescence quantum yield is 70% or more. An R dopant/B dopant ratio is 5 to 20 wt%, and a ratio of the B dopant to the entire luminescent layer is 10 to 30 wt%. <P>COPYRIGHT: (C)2013,JPO&INPIT |
