Polymer, organic solar cell comprising polymer, perovskite solar cell comprising polymer

An organic solar cell comprising:

• a first electrode and a second electrode disposed facing each other;
• and
• a photo-active layer disposed between the first electrode and the second electrode,
• wherein the photo-active layer comprises a polymer represented by Structural Formula 2:
• wherein in Structural Formula 2,
• X5, X6, X7 and X8 are each independently O, S, Se, NH, or NR″,
• R5 and R6 are each independently an alkyl group having 1 to 50 carbon atoms, an aryl group having 6 to 50 carbon atoms, or —(CH2CH2O)mCH3,
• A5, A6, A7, A8, A9, A10, A11, A12, A13, A14, A15, and A16 are each independently H, F, Cl, CN, —COOR″, —OR″, an alkyl group having 1 to 50 carbon atoms, or an aryl group having 6 to 50 carbon atoms,
• R″ is each independently an alkyl group having 1 to 50 carbon atoms, an aryl group having 6 to 50 carbon atoms, or —(CH2CH2O)mCH3,
• m is an integer ranging from 1 to 20, and
• n is an integer ranging from 1 to 1000,
• wherein lamellar stacking of the polymer for the photo-active layer has both edge-on orientation and face-on orientation, and
• wherein the polymer for the photo-active layer of an organic solar cell has a crystalline coherence length in a range of 19.5 Å to 22.0 Å.