An organic photoelectronic device comprising: a first electrode; a second electrode on the first electrode; a photoelectronic conversion layer between the first electrode and the second electrode, the photoelectronic conversion layer including a p-n junction, the p-n junction including a first material and a second material; and an interlayer adjacent to the first electrode, the interlayer being between the first electrode and the photoelectronic conversion layer and including a third material; wherein the photoelectronic conversion layer has a thickness of 1 nm to 500 nm, wherein each of the first material and the third material are an organic material having an energy bandgap of 1.7 eV to 2.3 eV, wherein the first material and the third material are the same or different, characterized in that the interlayer has a thickness of 0.1 nm to 50 nm and in that the first material and the third material each include a compound represented by Chemical Formula 1, wherein, in Chemical Formula 1, X is one of Se, Te, SO, SO 2, and SiR a R b, EDG is an electron donating group, EAG is an electron accepting group, each of R 1 and R 2 are independently one of hydrogen and a monovalent substituent, and each of R a and R b are independently one of hydrogen, a substituted or unsubstituted C 1 to C 30 alkyl group, a substituted or unsubstituted C 6 to C 30 aryl group, a substituted or unsubstituted C 3 to C 30 heteroaryl group, a substituted or unsubstituted C 1 to C 6 alkoxy group, a halogen, and a cyano group, wherein, the first material is represented by Chemical Formula 1A, and the third material is represented by Chemical Formula 1B, wherein, in Chemical Formulae 1A and 1B, X is one of Se, Te, SO, SO 2, and SiR a R b, Ar is one of a substituted or unsubstituted 5-membered aromatic ring, a substituted or unsubstituted 6-membered aromatic ring, and a fused ring of the two or more foregoing rings, each of Ar 1a, Ar 2a, Ar 1b, and Ar 2b are independently one of a substituted or unsubstituted C 6 to C 30 aryl group, and a substituted or unsubstituted C 3 to C 30 heteroaryl group, and each of R 1a to R 3a, R 1b to R 3b, R a, and R b are independently one of hydrogen, a substituted or unsubstituted C 1 to C 30 alkyl group, a substituted or unsubstituted C 6 to C 30 aryl group, a substituted or unsubstituted C 3 to C 30 heteroaryl group, a substituted or unsubstituted C 1 to C 6 alkoxy group, a halogen, and a cyano group. a first electrode; a second electrode on the first electrode; a photoelectronic conversion layer between the first electrode and the second electrode, the photoelectronic conversion layer including a p-n junction, the p-n junction including a first material and a second material; and an interlayer adjacent to the first electrode, the interlayer being between the first electrode and the photoelectronic conversion layer and including a third material; wherein the photoelectronic conversion layer has a thickness of 1 nm to 500 nm, wherein each of the first material and the third material are an organic material having an energy bandgap of 1.7 eV to 2.3 eV, wherein the first material and the third material are the same or different, characterized in that the interlayer has a thickness of 0.1 nm to 50 nm and in that the first material and the third material each include a compound represented by Chemical Formula 1, wherein, in Chemical Formula 1, X is one of Se, Te, SO, SO 2, and SiR a R b, EDG is an electron donating group, EAG is an electron accepting group, each of R 1 and R 2 are independently one of hydrogen and a monovalent substituent, and each of R a and R b are independently one of hydrogen, a substituted or unsubstituted C 1 to C 30 alkyl group, a substituted or unsubstituted C 6 to C 30 aryl group, a substituted or unsubstituted C 3 to C 30 heteroaryl group, a substituted or unsubstituted C 1 to C 6 alkoxy group, a halogen, and a cyano group, wherein, the first material is represented by Chemical Formula 1A, and the third material is represented by Chemical Formula 1B, wherein, in Chemical Formulae 1A and 1B, X is one of Se, Te, SO, SO 2, and SiR a R b, Ar is one of a substituted or unsubstituted 5-membered aromatic ring, a substituted or unsubstituted 6-membered aromatic ring, and a fused ring of the two or more foregoing rings, each of Ar 1a, Ar 2a, Ar 1b, and Ar 2b are independently one of a substituted or unsubstituted C 6 to C 30 aryl group, and a substituted or unsubstituted C 3 to C 30 heteroaryl group, and a substituted or unsubstituted C 6 to C 30 aryl group, and a substituted or unsubstituted C 3 to C 30 heteroaryl group, and each of R 1a to R 3a, R 1b to R 3b, R a, and R b are independently one of hydrogen, a substituted or unsubstituted C 1 to C 30 alkyl group, a substituted or unsubstituted C 6 to C 30 aryl group, a substituted or unsubstituted C 3 to C 30 heteroaryl group, a substituted or unsubstituted C 1 to C 6 alkoxy group, a halogen, and hydrogen, a substituted or unsubstituted C 1 to C 30 alkyl group, a substituted or unsubstituted C 6 to C 30 aryl group, a substituted or unsubstituted C 3 to C 30 heteroaryl group, a substituted or unsubstituted C 1 to C 6 alkoxy group, a halogen, and a cyano group.