Composition and organic light-emitting device including the same

A composition comprising:

• a platinum-containing organometallic compound, a first compound, a second compound, and a third compound,
• wherein the platinum-containing organometallic compound, the first compound, the second compound, and the third compound are different from each other,
• the first compound comprises at least one electron transport moiety,
• the second compound does not comprise an electron transport moiety,
• the third compound has a greater band gap than a band gap of the first compound and a band gap of the second compound,
• the platinum-containing organometallic compound is an organometallic compound represented by Formula 1-1 or 1-2:
• wherein, in Formulae 1-1 and 1-2,
• M is platinum (Pt),
• Y1 is O or S, and each of Y2 to Y4 is a chemical bond,
• each of X1 and X3 is C, and each of X2 and X4 is N,
• T1 is a single bond, a double bond, *—N(R51)—*′, *—B(R51)—*′, *—P(R51)—*′, *—C(R51)(R52)—*′, *—Si(R51)(R52)—*′, *—Ge(R51)(R52)—*′, *—S—*′, *—Se—*′, *—O—*′, *—C(═O)—*′, *—S(═O)—*′, *—S(═O)2—*—C(R51)=*′, *═C(R51)—*′, *—C(R51)═C(R52)—*′, *—C(═S)—*′, or *—C≡C—*′,
• T2 is a single bond, a double bond, *—N(R53)—*′, *—B(R53)—*′, *—P(R53)—*′, *—C(R53)(R54)—*′, *—Si(R53)(R54)—*′, *—Ge(R53)(R54)—*′, *—S—*′, *—Se—*′, *—O—*′, *—C(═O)-*′, *—S(═O)—*′, *—S(═O)2—*—C(R53)=*′, *═C(R53)—*′, *—C(R53)═C(R54)—*′, *—C(═S)—*′, or *—C≡C—*′,
• T3 is a single bond, a double bond, *—N(R55)—*′, *—B(R55)—*′, *—P(R55)—*′, *—C(R55)(R56)—*′, *—Si(R55)(R56)—*′, *—Ge(R55)(R56)—*′, *—S—*′, *—Se—*′, *—O—*′, *—C(═O)-*′, *—S(═O)—*′, *—S(═O)2—*—C(R55)=*′, *═C(R55)—*′, *—C(R55)═C(R56)—*′, *—C(═S)—*′, or *—C≡C*′,
• X11 is N or C-[(L11)a11-(R11)b11], X12 is N or C-[(L12)a12-(R12)b12], X13 is N or C-[(L13)a13-(R13)b13], and X14 is N or C-[(L14)a14-(R14)b14],
• X21 is N or C-[(L21)a21-(R21)b21], X22 is N or C-[(L22)a22-(R22)b22], and X23 is N or C-[(L23)a23-(R23)b23],
• X29 is O, S, C(R27)(R28), Si(R27)(R28), or N-[(L29)a29-(R29)b29],
• X31 is N or C-[(L31)a31-(R31)b31], X32 is N or C-[(L32)a32-(R32)b32], and X33 is N or C-[(L33)a33-(R33)b33],
• X41 is N or C-[(L41)a41-(R41)b41], X42 is N or C-[(L42)a42-(R42)b42], X43 is N or C-[(L43)a43-(R43)b43], and X44 is N or C-[(L44)a44-(R44)b44],
• L11 to L14, L21 to L23, L31 to L33, and L41 to L44 are each independently a single bond, a C5-C30 carbocyclic group unsubstituted or substituted with at least one R10a or a C1-C30 heterocyclic group unsubstituted or substituted with at least one R10a,
• a11 to a14, a21 to a23, a31 to a33, and a41 to a44 are each independently an integer from 1 to 10,
• R11 to R14, R21 to R23, R27 to R29, R31 to R33, and R41 to R44 are each independently hydrogen, deuterium, —F, —Cl, —Br, —I, —SF5, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof, 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 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 C6-C60 aryloxy group, a substituted or unsubstituted C6-C60 arylthio group, a substituted or unsubstituted C1-C60 heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —N(Q1)(Q2), —Si(Q3)(Q4)(Q5), —B(Q6)(Q7), or —P(═O)(Q8)(Q9),
• b11 to b14, b21 to b23, b29, b31 to b33, and b41 to b44 are each independently an integer from 1 to 10,
• two of R11 to R14 are optionally linked to each other form a C5-C30 carbocyclic group unsubstituted or substituted with at least one R10a or a C1-C30 heterocyclic group unsubstituted or substituted with at least one R10a,
• two of R21 to R23 are optionally linked to each other to form a C5-C30 carbocyclic group unsubstituted or substituted with at least one R10a or a C1-C30 heterocyclic group unsubstituted or substituted with at least one R10a,
• two of R31 to R33 are optionally linked to each other to form a C5-C30 carbocyclic group unsubstituted or substituted with at least one R10a or a C1-C30 heterocyclic group unsubstituted or substituted with at least one R10a, and
• two of R41 to R44 are optionally linked to each other to form a C5-C30 carbocyclic group unsubstituted or substituted with at least one R10a or a C1-C30 heterocyclic group unsubstituted or substituted with at least one R10a.