Light-emitting device and apparatus including the same

A light-emitting device comprising:

• a first electrode;
• a second electrode facing the first electrode;
• light-emitting units in the number of n between the first electrode and the second electrode;
• and
• a charge-generation unit(s) in the number of n−1 between the adjacent light-emitting units,
• wherein n is a natural number of 2 or more,
• the light-emitting units each comprise an emission layer,
• at least one of the charge-generation unit(s) comprises an n-type charge-generation layer, a p-type charge-generation layer, and an interlayer between the n-type charge-generation layer and the p-type charge-generation layer,
• the p-type charge-generation layer comprises a first material and a second material,
• the first material comprises a hole-transporting organic compound, an inorganic insulation compound, or any combination thereof,
• the second material comprises at least one inorganic semiconductor compound, and
• the interlayer consists of a third material, the third material being at least one selected from a quinone derivative, 1,4,5,8,9,11-hexaazatriphenylene-hexacarbonitrile (HAT-CN), and a compound represented by Formula 221:
• wherein in Formula 221,
• each of R221 to R223 is independently selected from a substituted or unsubstituted C3-C10 cycloalkyl group, a substituted or unsubstituted C1-C10 heterocycloalkyl group, a substituted or unsubstituted C3-C10 cycloalkenyl group, a substituted or unsubstituted C1-C10 heterocycloalkenyl group, a substituted or unsubstituted C6-C60 aryl group, a substituted or unsubstituted C1-C60 heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, and
• wherein at least one selected from R221 to R223 has at least one substituent selected from a cyano group, —F, —Cl, —Br, —I, a C1-C20 alkyl group substituted with —F, a C1-C20 alkyl group substituted with —Cl, a C1-C20 alkyl group substituted with —Br, and a C1-C20 alkyl group substituted with —I.