Polycyclic compound, light-emitting device and electronic device

A light-emitting device, comprising:

• a first electrode;
• a second electrode;
• and
• an intermediate layer between the first electrode and the second electrode, wherein the intermediate layer comprises at least one light-emitting structure comprising a hole transfer region, an emission layer and an electron transfer region, and the emission layer comprises a polycyclic compound represented by Chemical Formula 1:
• wherein, in Chemical Formula 1, X1 to X4 are each independently O, S, Se, or NR15, and when the number of NR15 is two or more, each R15 is independently the same or different,
• R1 to R15, and RA and RB are each independently hydrogen, deuterium, —OH, —CN, —F, —Cl, —Br, —I, —SF5, -CD3, -CD2H, -CDH2, —CF3, —CF2H, —CFH2, a substituted or unsubstituted C1-C60 alkyl group, a substituted or unsubstituted C2-C60 alkenyl group, a substituted or unsubstituted C2-C60 alkynyl group, a substituted or unsubstituted C1-C60 alkoxy group, a substituted or unsubstituted C1-C60 alkylthio group, a substituted or unsubstituted C3-C60 cycloalkyl group, a substituted or unsubstituted C5-C60 cycloalkenyl group, a substituted or unsubstituted C1-C60 heterocycloalkyl group, a substituted or unsubstituted C1-C60 heterocycloalkenyl group, a substituted or unsubstituted C6-C60 aryl group, a substituted or unsubstituted C7-C60 arylalkyl group, a substituted or unsubstituted C7-C60 alkyl aryl group, a substituted or unsubstituted C2-C60 heteroaryl group, a substituted or unsubstituted C3-C60 alkyl heteroaryl group, a substituted or unsubstituted C3-C60 heteroarylalkyl group, a substituted or unsubstituted C6-C60 aryloxy group, a substituted or unsubstituted C6-C60 arylthio group, a substituted or unsubstituted C8-C60 condensed polycyclic group, or a substituted or unsubstituted silyl group,
• two or more adjacent groups among R1 to R15, and RA and RB are optionally combined with each other to form a saturated or unsaturated ring, and
• at least one of RA and RB is a substituted or unsubstituted triazine group.