The diketopyrrolopyrrole-based copolymers PDPP-BBT and TDPP-BBT were synthesized and used as a donor for bulk heterojunction photovoltaic devices. The photophysical properties of these polymers showed absorption in the range 500− 600 nm with a maximum peak around 563 nm, while TDPP-BBT showed broadband absorption in the range 620− 800 nm with a peak around 656 nm. The power conversion efficiencies (PCE) of the ...