| 摘要 |
<p>An organic EL element (10) comprising a substrate (11), and an anode (12), a hole injection layer (13), a multilayer for suppressing transportation of electrons (14), a light emitting layer (15), an electron transportation layer (16), and a cathode (18) all formed sequentially on the substrate (11), wherein the hole injection layer (13) is composed of a hole transportation material doped with acceptor, and the multilayer for suppressing transportation of electrons (14) comprises a first electron transportation suppressing layer (14A1), a second electron transportation suppressing layer (14B1), and a first electron transportation suppressing layer (14A2) formed sequentially from the light emitting layer (15) side toward the hole injection layer (13). Conductivity is enhanced by doping the hole injection layer (13) with acceptor and the flow of hole current is prevented from being impeded by confining electrons surely in the light emitting layer (15) by means of the first and second electron transportation suppressing layer (14A1, 14B1) and making thin the first and second electron transportation suppressing layer (14A1, 14B1). Emission efficiency is thereby enhanced while prolonging the lifetime.</p> |
