Patent ID: 7504161

Claim:
A light-emitting element, which comprises a substrate having provided thereon a pair of opposed electrodes between which are provided a light-emitting layer containing at least one light-emitting material selected from the compounds represented by the following general formula (I) and a host material, and which comprises an organic membrane having a larger ionization potential than that of the host material between the light-emitting layer and a cathode, the organic membrane being in contact with the light-emitting layer: wherein R 1 , R 3 , R 4 and R 5 may be the same or different from each other and each represents a hydrogen atom or a substituent, X represents an oxygen atom, a sulfur atom or N—R Y1 , R Y1 represents a hydrogen atom or a substituent, L represents a linking group comprising a conjugated bond, R X and R Y may be the same or different from each other and each represents a hydrogen atom or a substituent, with at least one of them being an electron-withdrawing group, wherein the organic membrane comprises at least one compound selected from the compounds represented by the general formula (E 12): wherein, in the general formula (E 12) X E represents O, S, N—R a or C—R a , R a represents a hydrogen atom or a substituent, Z b represents atoms necessary for forming a pyrimidine ring, a pyridazine ring, a pyrrole ring, a furan ring, a thiophene ring, a selenophene ring, a tellurophene ring, an imidazole ring, a thiazole ring, a selenazole ring, a tellurazole ring, a thiadiazole ring, an oxadiazole ring and a pyrazole ring, m 6 represents an integer of 2 or more, and L 6 represents a linking group.