LIGHT-EMITTING ELEMENT, LIGHT-EMITTING DEVICE, ELECTRONIC DEVICE, AND LIGHTING DEVICE

摘要

A light-emitting element which emits light with high luminance and can be driven at low voltage. The light-emitting element includes n (n is a natural number of 2 or more) EL layers between an anode and a cathode, and includes a first layer, a second layer, and a third layer between an m-th (m is a natural number, 1≰m≰n−1) EL layer from the anode and an (m+1)th EL layer. The first layer functions as a charge-generation region, has hole-transport properties, and contains an acceptor substance. The third layer has electron-transport properties and contains an alkali metal or the like. The second layer formed of a metal complex having a metal-oxygen bond and an aromatic ligand is provided between the first and third layers, whereby an injection barrier at the time of injecting electrons generated in the first layer into the m-th EL layer through the third layer can be lowered.