An organic thin film transistor comprising a gate electrode, an insulating layer, a source electrode, a drain electrode, an organic semi-conducting layer and at least one organic layer comprising a compound represented by the following formula 2, the organic layer(s) comprising a compound represented by formula 2 being located between the organic semi-conducting layer and at least one of the source electrode and the drain electrode, and being in contact with at least one of the source electrode and the drain electrode: wherein: n is 0 or 1; R9 to R18 are each independently selected from hydrogen, a halogen group, a nitrile group (-CN), a nitro group (-NO 2), a sulfonyl group (-SO 2 R), a sulfoxide group (-SOR), a sulfonamide group (-SO 2 NRR'), a sulfonate group (-SO 3 R), a trifluoromethyl group (-CF 3), an ester group (COOR), an amide group (-CONHR, -CONRR'), a substituted or unsubstituted straight-chained or branched C 1 -C 12 alkoxy group, a substituted or unsubstituted straight-chained or branched C 1 -C 12 alkyl group, a substituted or unsubstituted aromatic or non-aromatic heterocyclic group, a substituted or unsubstituted C 6 -C 20 aryl group, a substituted or unsubstituted amine group (-NHR, -NRR') and -L-M, and R9 and R10, or R11 and R12 may be bonded together to form an aromatic or heterocyclic ring; L is a C 1 -C 60 alkylene group which is unsubstituted or substituted with at least one group selected from an amine group (-NHR, -NRR'), an amide group (-NHCOR, -CONHR, -CONRR'), an ether group (-COR) and an ester group (-COOR); a C 6 -C 60 arylene group which is unsubstituted or substituted with at least one group selected from an amine group (-NHR, -NRR'), an amide group (-NHCOR, -CONHR, -CONRR'), an ether group (-COR) and an ester group (-COOR); or a 5- to 7-membered heterocyclic group which is unsubstituted or substituted with at least one group selected from an amine group (-NHR, -NRR'), an amide group (-NHCOR, -CONHR, -CONRR'), an ether group (-COR) and an ester group (-COOR); M is selected from an alcohol group (-OH), a thio group (-SH), a phosphate group (-PO 3 H), an amine group (-NHR, -NRR'), a substituted or unsubstituted polyolefin, a substituted or unsubstituted polyvinyl, a substituted or unsubstituted polyacrylate, a substituted or unsubstituted polythiophene, a substituted or unsubstituted polypyrrole, and a substituted or unsubstituted polyaniline; and R and R' are the same or different and are each independently hydrogen, a substituted or unsubstituted C 1 -C 60 alkyl group, a substituted or unsubstituted C 6 -C 60 aryl group, or a substituted or unsubstituted 5- to 7-membered heterocyclic group. n is 0 or 1; R9 to R18 are each independently selected from hydrogen, a halogen group, a nitrile group (-CN), a nitro group (-NO 2), a sulfonyl group (-SO 2 R), a sulfoxide group (-SOR), a sulfonamide group (-SO 2 NRR'), a sulfonate group (-SO 3 R), a trifluoromethyl group (-CF 3), an ester group (COOR), an amide group (-CONHR, -CONRR'), a substituted or unsubstituted straight-chained or branched C 1 -C 12 alkoxy group, a substituted or unsubstituted straight-chained or branched C 1 -C 12 alkyl group, a substituted or unsubstituted aromatic or non-aromatic heterocyclic group, a substituted or unsubstituted C 6 -C 20 aryl group, a substituted or unsubstituted amine group (-NHR, -NRR') and -L-M, and R9 and R10, or R11 and R12 may be bonded together to form an aromatic or heterocyclic ring; L is a C 1 -C 60 alkylene group which is unsubstituted or substituted with at least one group selected from an amine group (-NHR, -NRR'), an amide group (-NHCOR, -CONHR, -CONRR'), an ether group (-COR) and an ester group (-COOR); a C 6 -C 60 arylene group which is unsubstituted or substituted with at least one group selected from an amine group (-NHR, -NRR'), an amide group (-NHCOR, -CONHR, -CONRR'), an ether group (-COR) and an ester group (-COOR); or a 5- to 7-membered heterocyclic group which is unsubstituted or substituted with at least one group selected from an amine group (-NHR, -NRR'), an amide group (-NHCOR, -CONHR, -CONRR'), an ether group (-COR) and an ester group (-COOR); M is selected from an alcohol group (-OH), a thio group (-SH), a phosphate group (-PO 3 H), an amine group (-NHR, -NRR'), a substituted or unsubstituted polyolefin, a substituted or unsubstituted polyvinyl, a substituted or unsubstituted polyacrylate, a substituted or unsubstituted polythiophene, a substituted or unsubstituted polypyrrole, and a substituted or unsubstituted polyaniline; and R and R' are the same or different and are each independently hydrogen, a substituted or unsubstituted C 1 -C 60 alkyl group, a substituted or unsubstituted C 6 -C 60 aryl group, or a substituted or unsubstituted 5- to 7-membered heterocyclic group.