Polymer and organic electronic device using same

A polymer comprising:

• a repeating unit represented by the following Chemical Formula 1 and a repeating unit represented by Chemical Formula 2:
• wherein
• R1 to R4 are independently of one another C1-C30 alkyl;
• X1 to X4 are independently of one another O, S, or Se;
• V1 and V2 are independently of each other a fused ring having methylidene as a linking group, the fused ring may be independently of each other further substituted by one or more substituents selected from C1-C30 alkyl, C1-C30 alkoxy, C1-C30 alkylthio, halogen, cyano, haloC1-C30 alkyl, nitro, and hydroxy, —CH2— of the fused ring may be replaced with carbonyl, thiocarbonyl, or
• in which R is independently of each other hydrogen, C1-C30 alkyl, C1-C30 alkoxy, C1-C30 alkylthio, halogen, cyano, nitro, hydroxy, haloC1-C30 alkyl, C1-C30 alkylcarbonyl, or C1-C30 alkylcarbonyloxy, and the fused ring may include one or more heteroatoms selected from N, O, S, and Se;
• and
• Ar is benzodithiophenylene, benzodithienothiophenylene, naphthodithiophenylene, thiophenylene, benzothienoselenophenylene, benzodiselenophenylene, benzodiselenoselenophenylene, naphthodiselenophenylene, selenophenylene, or a combination thereof, and Ar may be independently of each other further substituted by one or more substituents selected from C1-C30 alkyl, C1-C30 alkoxy, C1-C30 alkylthio, C6-C30 aryl, C3-C30 heteroaryl, halogen, cyano, nitro, hydroxy, and a combination thereof.