ORGANIC EL ELEMENT

• Main Author: SATO JURI
• Format: Patent
• Language: English; Japanese
• Published: 02.07.2015
• Subjects: CHEMISTRY; ELECTRICITY; HETEROCYCLIC COMPOUNDS; METALLURGY; ORGANIC CHEMISTRY

PROBLEM TO BE SOLVED: To provide an organic EL element capable of improving luminous efficiency furthermore while suppressing an increase in driving voltage.SOLUTION: An organic EL element according to the present invention includes: an anode; a hole transport layer provided on the anode and comprising a plurality of layers main components of which are different compounds from each other; a luminous layer provided on the hole transport layer; and a cathode provided on the luminous layer. The hole mobility in a first hole transport layer having the highest thickness among the hole transport layers comprising a plurality of layers is higher than the hole mobility in at least one layer among the hole transport layers located between the first hole transport layer and the luminous layer. 【課題】駆動電圧の増加を抑制しつつ、発光効率を更に向上させることが可能な、有機ＥＬ素子を提供すること。【解決手段】本発明に係る有機ＥＬ素子は、陽極と、前記陽極上に設けられ、互いに異なる化合物を主成分とする複数層からなる正孔輸送層と、前記正孔輸送層上に設けられる発光層と、前記発光層上に設けられる陰極と、を備え、前記複数層からなる正孔輸送層のうち最も厚みが厚い第１の正孔輸送層における正孔移動度が、当該第１の正孔輸送層と前記発光層との間に位置する前記正孔輸送層のうち少なくとも１層における正孔移動度よりも大きい。【選択図】図１