Plurality of host materials and organic electroluminescent device comprising the same

A plurality of host materials comprising a first host material comprising a compound represented by the following formula 1-1 or 1-2, and a second host material comprising a compound represented by the following formula 2:

• wherein
• X1 represents —N═;
• Y1 represents —O—, or —S;
• L1 represents a single bond, or a deuterium-substituted or unsubstituted (C6-C30) arylene;
• Ar1 represents a di-(C6-C30) arylamino unsubstituted or substituted with at least one of deuterium and (C1-C30)alkyl, or a (C6-C30) aryl(3- to 30-membered) heteroarylamino unsubstituted or substituted with at least one of deuterium and (C6-C30) aryl;
• R11 represents a deuterium-substituted or unsubstituted (C6-C30) aryl;
• R12 to R14 each independently represent hydrogen or deuterium;
• a and b each independently represent 1 or 2, and c is an integer of 1 to 3, where if a to c are an integer of 2 or more, each of R12 to each of R14 may be the same or different;
• wherein
• HAr represents a substituted triazinyl having two substituents, wherein one substituent is a naphthyl unsubstituted or substituted with deuterium, and the other substituent is selected from the group consisting of phenyl, naphthyl, biphenyl, phenanthrenyl and terphenyl, and each optionally further substituted with deuterium;
• L2 represents a naphthylene unsubstituted or substituted with deuterium;
• and
• R1 to R8 each independently represent hydrogen, deuterium, or a (C6-C30) aryl unsubstituted or substituted with deuterium.