An oxindole-based monomer, (Z)-3-(thiophen2-yl-methylene)indolin-2-one (TEI) has been synthesized. The hemi-isoindigo, TEI was polymerized separately with bis(trimethylstannyl) functionalized thiophene, bis(alkoxy)benzodithiophene, and bis(alkylthienyl)benzodithiophene to form polymers PTEI-T, PTEI-BDTO, and PTEI-BDTT, respectively. These new conjugated polymers showed low-lying HOMO energy levels (-5.26 to -5.42 eV), suitable LUMO energy levels (-3.63 to -3.66 eV), strong absorption in visible region and extended to near-IR The inverted bulk heterojunction (BHJ) polymer solar cells based on the new polymers were fabricated and tested. The solar cell devices based on the blend of PTEI-T:[6,6]-phenyl-C-61-butyric acid methyl ester (PC61BM) achieved a short-circuit current density (J(sc)) value of 13.4 mA cm(-2), a fill factor (FF) of 0.65, an open circuit voltage (voc) of 0.85 V, and a power conversion efficiency (PCE) of 7.32%. The high performance solar cell devices were realized with the polymer which had a relatively simple structure.