Copolymers (RP1−4) prepared using four differently modified synthetic procedures.
The calculated optical band gaps are 1.91 eV for RP1 and 1.85 eV for RP2−4.
The HOMO energy levels (−5.37 eV) of all four copolymers are identical.
All four copolymers exhibited a hole mobility in the order of 10−4 cm2 V−1 s−1.
The achieved maximum PCE is 5.84%, 5.23%, 5.08%, and 4.86%, respectively.