Polymer and organic solar cell comprising same

A polymer comprising:

• a first unit of Chemical Formula 1;
• and
• a second unit of Chemical Formula 2:
• wherein:
• d1, d2, x, and x′ are each 1 or 2;
• when d1, d2, x, and x′ are each 2, structures in the parenthesis are the same as or different from each other;
• X1 and X2 are the same as or different from each other, and are each independently CRR, NR, O, SiRR′, PR, S, GeRR′, Se or Te;
• Y1 to Y4 are the same as or different from each other, and are each independently CR″, N, SiR″, P, or GeR″;
• X and X′ are the same as or different from each other, and are each independently S or Se;
• Ar1 and Ar2 are the same as or different from each other, and are each independently a substituted or unsubstituted straight or branched alkyl group;
• R1 and R2 are the same as or different from each other, and are each independently a substituted or unsubstituted branched alkyl group;
• G1 and G2 are the same as or different from each other, and are each independently hydrogen, or fluorine;
• R, R′, and R″ are the same as or different from each other, and are each independently hydrogen, deuterium, a halogen group, a hydroxy group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group;
• and
• D1 and D2 are the same as or different from each other, and are each independently any one selected from the following structures,
• wherein:
• X″, X′″, and X″″ are the same as or different from each other, and are each independently S or Se;
• Y and Y′ are the same as or different from each other, and are each independently CR′″, N, SiR′″, P, or Ge R′″;
• G11 to G18, G101, and G102 are the same as or different from each other, and are each independently hydrogen, or fluorine;
• R′″ is hydrogen, deuterium, a halogen group, a hydroxy group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group;
• and
• g is 0 or 1.