Two novel conjugated polymers based on 3,4-ethylenedithiathiophene (EDTT) were designed and synthesized through the palladium-catalyzed Suzuki coupling method and Stille cross-coupling reactions. Conventional and inverted cells were fabricated and device processing conditions were optimized, respectively. The maximum power conversion efficiency (PCE) of 2.4% was obtained with an open-circuit voltage (Voc) of 0.69 V, a short circuit current (Jsc) of 6.62 mA cm−2, and a fill factor (FF) of 53%, respectively.
