Abstract: Provided is a compound of Chemical Formula 1 or 2: wherein: R1 to R4 are each independently hydrogen or deuterium; n1 to n4 are an integer of 1 to 4; L1 and L2 are each independently a direct bond or a substituted or unsubstituted C6-60 arylene; and Ar1 and Ar2 are each independently a substituent of Chemical Formula 3: wherein X1 to X5 are each independently N or C(R5), wherein at least two of X1 to X5 are N; and each R5 is independently hydrogen, deuterium, a substituted or unsubstituted C1-20 alkyl, a substituted or unsubstituted C6-60 aryl, or a substituted or unsubstituted C2-60 heteroaryl containing at least one of N, O and S, or two adjacent R5s combine to form a benzene ring; and an organic light emitting device including the same. The device exhibits significantly superior efficiency and lifespan.

Abstract: Provided is an organic light-emitting device comprising: a light emitting layer comprising a compound of the following Chemical Formula 1, and one or more of an electron transport layer, an electron injection layer, or an electron transport and injection layer that comprises at least one of a compound of the following Chemical Formula 2 and a compound of the following Chemical Formula 3: wherein Ar2 and Ar3 are each independently a substituent of Chemical Formula 4, where X1 to X5 are each independently N or C(R8), wherein at least two of X1 to X5 are N, and the other substituents are as defined in the specification. The organic light emitting device including the heterocyclic compound of Chemical Formula 1 and the heterocyclic compound of Chemical Formula 2 or 3 had significantly superior efficiency and lifespan.

Abstract: Provided is a compound of Chemical Formula 1: wherein: L1 and L2 are the same as or different from each other, and are each independently an arylene group which is unsubstituted or substituted with an aryl group, Ar1 and Ar2 are the same as or different from each other, and are each independently the following Chemical Formula A, where X1 is N or CR1, X2 is N or CR2, X3 is N or CR3, X4 is N or CR4, and X5 is N or CR5, at least two of X1 to X5 are N, and the other substituents are as defined in the specification, and an organic light emitting device including the same. The organic light emitting device including the compound of Chemical Formula 1 exhibits remarkably excellent characteristics in terms of voltage, efficiency and service life.