| 摘要 |
PROBLEM TO BE SOLVED: To improve the stability while enabling the drive with high light emitting efficiency in a long wavelength (red) area by including phenoxazone derivative in at least one layer among layers mainly composed of the organic material between a positive electrode and a negative electrode opposite to each other. SOLUTION: Phenoxazone derivative expressed with a formula I, for example, a compound expressed with a formula II is included in a hole transporting layer and an electron transporting layer as organic material layers of an organic electroluminescent element. This derivative has strong fluorescent intensity in the distributed condition, and has excellent light resistance and the heat resistance. Light emitting characteristic in the visible long wavelength area of an element using this derivative can be improved, and excellent light color emission is obtained, and it can be used for flat panel display capable of displaying in full color. In the formula I, R1-R9 means hydrogen, halogen, alkyl group, alkenyl group, cyano group, carboxyl group, saturated heterocyclic group, OR group, (R means alkyl group, aromatic group hydrocarbon group or the like); and any one pair of R5 and R6, R6 and R7, R7 and R8 can be connected to each other so as to form a ring.
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