A hetero-cyclic compound represented by any one of the following Formulae 4 to 7: in Formula 4 to 7, Y is S or O, R4 to R9 are the same as or different from each other, and are each independently selected from the group consisting of hydrogen; and deuterium; at least one of R1 to R3 is - m- n, the other is selected from the group consisting of hydrogen; or monocyclic or polycyclic substituted or unsubstituted C6 to C60 aryl; L is straight-chained or branched substituted or unsubstituted C2 to C60 alkylene; monocyclic or polycyclic substituted or unsubstituted C2 to C60 arylene; or monocyclic or polycyclic substituted or unsubstituted C2 to C60 heteroarylene, m is an integer of 0 to 3, n is an integer of 1 or 2, Z is selected from substituted or unsubstituted biphenyl, substituted or unsubstituted triphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted anthracenyl, substituted or unsubstituted phenanthrenyl, substituted or unsubstituted indenyl, substituted or unsubstituted perylenyl, substituted or unsubstituted pyrenyl, substituted or unsubstituted acenaphthalenyl, substituted or unsubstituted fluorenyl, substituted or unsubstituted fluoranthenyl, substituted or unsubstituted triphenylenyl, substituted or unsubstituted phenalenyl, substituted or unsubstituted pyrrole, substituted or unsubstituted pyridyl, substituted or unsubstituted pyrimidyl, substituted or unsubstituted pyridazinyl, substituted or unsubstituted triazinyl, substituted or unsubstituted thienyl, substituted or unsubstituted furanyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted benzothiazole, substituted or unsubstituted benzoxazole, substituted or unsubstituted indolyl, substituted or unsubstituted carbazolyl, substituted or unsubstituted benzocarbazolyl, substituted or unsubstituted dibenzocarbazolyl, substituted or unsubstituted indolocarbazolyl, substituted or unsubstituted quinolyl, substituted or unsubstituted isoquinolyl, substituted or unsubstituted thiophenyl, substituted or unsubstituted benzothiophenyl, substituted or unsubstituted dibenzothiophenyl, substituted or unsubstituted indolinyl, a substituted or unsubstituted 10,11-dihydro-dibenzo[b,f]azepine group, a substituted or unsubstituted 9,10-dihydroacridine group, a substituted or unsubstituted spiro group in which 2,3-dihydro-1H-indene or cyclohexane is spiro-bonded to fluorene, substituted or unsubstituted diarylamine, a substituted or unsubstituted acetophenone group, a substituted or unsubstituted benzophenone group, - SiR11R12R13 and -P(=O)R14R15, and R11 to R15 are the same as or different from each other, and are each independently selected from the group consisting of straight-chained or branched C1 to C60 alkyl; monocyclic or polycyclic C6 to C60 aryl; and monocyclic or polycyclic C2 to C60 heteroaryl. Y is S or O, R4 to R9 are the same as or different from each other, and are each independently selected from the group consisting of hydrogen; and deuterium; at least one of R1 to R3 is - m- n, the other is selected from the group consisting of hydrogen; or monocyclic or polycyclic substituted or unsubstituted C6 to C60 aryl; L is straight-chained or branched substituted or unsubstituted C2 to C60 alkylene; monocyclic or polycyclic substituted or unsubstituted C2 to C60 arylene; or monocyclic or polycyclic substituted or unsubstituted C2 to C60 heteroarylene, m is an integer of 0 to 3, n is an integer of 1 or 2, Z is selected from substituted or unsubstituted biphenyl, substituted or unsubstituted triphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted anthracenyl, substituted or unsubstituted phenanthrenyl, substituted or unsubstituted indenyl, substituted or unsubstituted perylenyl, substituted or unsubstituted pyrenyl, substituted or unsubstituted acenaphthalenyl, substituted or unsubstituted fluorenyl, substituted or unsubstituted fluoranthenyl, substituted or unsubstituted triphenylenyl, substituted or unsubstituted phenalenyl, substituted or unsubstituted pyrrole, substituted or unsubstituted pyridyl, substituted or unsubstituted pyrimidyl, substituted or unsubstituted pyridazinyl, substituted or unsubstituted triazinyl, substituted or unsubstituted thienyl, substituted or unsubstituted furanyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted benzothiazole, substituted or unsubstituted benzoxazole, substituted or unsubstituted indolyl, substituted or unsubstituted carbazolyl, substituted or unsubstituted benzocarbazolyl, substituted or unsubstituted dibenzocarbazolyl, substituted or unsubstituted indolocarbazolyl, substituted or unsubstituted quinolyl, substituted or unsubstituted isoquinolyl, substituted or unsubstituted thiophenyl, substituted or unsubstituted benzothiophenyl, substituted or unsubstituted dibenzothiophenyl, substituted or unsubstituted indolinyl, a substituted or unsubstituted 10,11-dihydro-dibenzo[b,f]azepine group, a substituted or unsubstituted 9,10-dihydroacridine group, a substituted or unsubstituted spiro group in which 2,3-dihydro-1H-indene or cyclohexane is spiro-bonded to fluorene, substituted or unsubstituted diarylamine, a substituted or unsubstituted acetophenone group, a substituted or unsubstituted benzophenone group, - SiR11R12R13 and -P(=O)R14R15, and R11 to R15 are the same as or different from each other, and are each independently selected from the group consisting of straight-chained or branched C1 to C60 alkyl; monocyclic or polycyclic C6 to C60 aryl; and monocyclic or polycyclic C2 to C60 heteroaryl.