wherein, in Formula 1,

ring A is selected from a benzene group, a pyridine group, a pyridazine group, a pyrimidine group, a pyrazine group, a naphthalene group, a quinoline group, an isoquinoline group, a cinnoline group, a quinazoline group, a quinoxaline group, naphthyridine group, an anthracene group, a phenanthrene group, a benzoquinoline group, a phenanthridine group, an acridine group, phenanthroline group, and a phenazine group,

X₁ is C(R₁) and X₂ is N, or X₁ is N and X₂ is C(R₂),

one of R₁ to R₃ is a group represented by Formula 2-5,

the remainder of R₁ to R₃ are each independently hydrogen, a substituted or unsubstituted C₆-C₆₀ aryl group, or a substituted or unsubstituted C₁-C₆₀ heteroaryl group,

R₄ to R₁₁ are each independently hydrogen or deuterium,

L₁₁ is selected from a substituted or unsubstituted C₆-C₆₀ arylene group and a substituted or unsubstituted C₁-C₆₀ heteroarylene group,

a11 is 0, 1, or 2,

Ar₇ is selected from groups represented by Formulae 6-17 and 6-18 in case that A is a benzene group, and

Ar₇ is selected from groups represented by Formulae 6-12, 6-14,6-15, 6-17, and 6-18 in case that A is selected from a pyridine group, a pyridazine group, a pyrimidine group, a pyrazine group, a naphthalene group, a quinoline group, an isoquinoline group, a cinnoline group, a quinazoline group, a quinoxaline group, naphthyridine group, an anthracene group, a phenanthrene group, a benzoquinoline group, a phenanthridine group, an acridine group, phenanthroline group, and a phenazine group:

wherein, in Formulae 6-12, 6-14,6-15, 6-17, and 6-18, * indicates a binding site to a neighboring atom,

c3 is 1, 2, 3, 4, 5, or 6,

at least one of substituents of the substituted C₆-C₆₀ arylene group, the substituted C₁-C₆₀ heteroarylene group, and the substituted C₆-C₆₀ aryl group is selected from

deuterium (-D), a cyano group, a C₆-C₆₀ aryl group, and a C₁-C₆₀ heteroaryl group, and

* indicates a binding site to a neighboring atom.