Patent ID: 7429822

Claim:
An organic EL device comprising: an anode electrode; a cathode electrode having optical transparency; and an organic EL layer disposed between said anode electrode and said cathode electrode and including at least a fluorescent layer; wherein said cathode electrode has a metal layer and a conductive oxide layer arranged in this order from the organic EL layer side; the metal layer includes a first metal and a low work function metal, where a work function of said low work function metal is smaller than a work function of said first metal; said metal layer has a first surface on the organic EL layer side and a second surface on the conductive oxide layer side, and a concentration of said low work function metal at said first surface is greater than a concentration of said low work function metal at said second surface; said organic EL device is a polymer type organic EL device; said metal layer includes a first metal layer including said first metal and said low work function metal, and a second metal layer including a second metal, arranged in the order of the first metal layer and the second metal layer from the organic EL layer side; said second metal layer includes substantially none of said low work function metal, or said second metal layer includes said low work function metal in a concentration that is lower than the concentration of said low work function metal in said first metal layer; and the second metal layer includes substantially no organic material.