Patent ID: 8906517

Claim:
A display device comprising: a plurality of light emission units, each unit including an organic layer and an electron injecting layer, the plurality of light emission units laminated between an anode and a cathode; and a connection layer provided between each of the light emission units, wherein, the organic layer in each light emission unit includes a hole injection layer, a hole transporting layer, a light emission layer, an electron transporting layer in direct succession in the recited order, the electron injecting layer in each light emission unit and the connecting layer each includes the following layers successively laminated including (1) a buffer layer of a thickness of 1 nm or less in contact with at least the organic layer of one light emission unit, the buffer layer (a) employing an oxide which contains at least one of an alkali metal and an alkaline-earth metal, and (b) the buffer layer having a hole blocking property resulting from disposing the buffer layer in contact with the organic layer, (2) a mixed layer employing a charge transporting organic material having an electron transporting property and a metal material having an electron injecting property, the metal material reacts while reducing the charge transporting organic material to become transparent to ensure the electron injecting property, and (3) a protective layer, the protective layer of the connection layer has a triphenylene layer containing at least one of triphenylene derivatives and azatriphenylene derivatives represented by the following general formula (1) as a boundary layer of the cathode side: in which R 1 to R 6 each represents independently a hydrogen, halogen, hydroxyl group, amino group, arylamino group, substituted or not-substituted carbonyl group of 20 or less carbon atoms, substituted or not-substituted carbonyl ester group of 20 or less carbon atoms, substituted or not-substituted alkyl group of 20 or less carbon atoms, substituted or not-substituted alkenyl group of 20 or less carbon atoms, substituted or not-substituted alkoxyl group of 20 or less carbon atoms, substituted or not-substituted aryl group of 30 or less carbon atoms, substituted or not-substituted heterocyclic group of 30 or less carbon atoms, or a substituent selected from nitrile group, nitro group, cyano group, or silyl group, adjacent R m , where m=1 to 6, may join to each other by way of a cyclic structure and, further, x 1 to x 6 in the formula (1) each represents independently a carbon or nitrogen atom, wherein an organic material represented by the formula (1) is a material of the following formula (2):