An ink composition, comprising: a quantum dot; a metal catalyst; an aromatic halide compound; an ene compound comprising at least one C-H moiety and a carbon-carbon double bond; and optionally, a metal oxide particle, wherein the metal catalyst comprises a metal salt, a metal coordination complex, or a combination thereof, and wherein the metal catalyst comprises a metal that is palladium, nickel, ruthenium, rhodium, iridium, iron, cobalt, chromium, copper, platinum, silver, or gold, wherein the aromatic halide compound comprises a first aromatic halide having a first center aromatic moiety and at least two halogen groups linked to the first center aromatic moiety, wherein the first aromatic halide comprises a compound represented by Chemical Formula 1: wherein in Chemical Formula 1, each R is independently a substituted or unsubstituted C1 to C30 alkyl group; a substituted or unsubstituted C2 to C30 alkyl group in which at least one methylene is replaced with carbonyl, ether, ester, or a combination thereof; a substituted or unsubstituted C1 to C30 alkoxy group; a trialkylsilyl group; a substituted or unsubstituted C6 to C40 aryl group; or a substituted or unsubstituted C3 to C40 heteroaryl group, m is 0 or an integer of 1 or greater, n is an integer of 2 or greater, Ar is a substituted or unsubstituted C6 to C40 arene, a substituted or unsubstituted C3 to C40 heteroarene, a substituted or unsubstituted C9 to C40 polycyclic aromatic hydrocarbon, a substituted or unsubstituted C9 to C40 polycyclic heteroaromatic hydrocarbon, or a group having two or three arenes linked through nitrogen or a nitrogen containing moiety with each other, and each X is independently F, C!, Br, or I; and wherein the ink composition has a vapor pressure of less than or equal to 400 Pa (3 mmHg) at 20 °C. a quantum dot; a metal catalyst; an aromatic halide compound; an ene compound comprising at least one C-H moiety and a carbon-carbon double bond; and optionally, a metal oxide particle, wherein the metal catalyst comprises a metal salt, a metal coordination complex, or a combination thereof, and wherein the metal catalyst comprises a metal that is palladium, nickel, ruthenium, rhodium, iridium, iron, cobalt, chromium, copper, platinum, silver, or gold, wherein the aromatic halide compound comprises a first aromatic halide having a first center aromatic moiety and at least two halogen groups linked to the first center aromatic moiety, wherein the first aromatic halide comprises a compound represented by Chemical Formula 1: wherein in Chemical Formula 1, each R is independently a substituted or unsubstituted C1 to C30 alkyl group; a substituted or unsubstituted C2 to C30 alkyl group in which at least one methylene is replaced with carbonyl, ether, ester, or a combination thereof; a substituted or unsubstituted C1 to C30 alkoxy group; a trialkylsilyl group; a substituted or unsubstituted C6 to C40 aryl group; or a substituted or unsubstituted C3 to C40 heteroaryl group, m is 0 or an integer of 1 or greater, n is an integer of 2 or greater, Ar is a substituted or unsubstituted C6 to C40 arene, a substituted or unsubstituted C3 to C40 heteroarene, a substituted or unsubstituted C9 to C40 polycyclic aromatic hydrocarbon, a substituted or unsubstituted C9 to C40 polycyclic heteroaromatic hydrocarbon, or a group having two or three arenes linked through nitrogen or a nitrogen containing moiety with each other, and each X is independently F, C!, Br, or I; and wherein the ink composition has a vapor pressure of less than or equal to 400 Pa (3 mmHg) at 20 °C.