PCDTBT: en route for low cost plastic solar cells

Since its inception in 1995, significant advances in the field of bulk heterojunction (BHJ) solar cells have been made and polymeric semiconductors are now considered to be one of the most promising ways to lower the cost of the energy generated by solar cells. Power conversion efficiencies (PCEs) are now reaching the threshold values for commercialisation (9.2% for single-layer BHJ and 10.6% for tandem devices). PCDTBT, a carbazole-based copolymer, is among the most efficient, stable and low-cost materials for BHJ solar cells with a high open-circuit voltage (V-oc similar to 0.90 V), power conversion efficiency of 7.5% and estimated lifetime of 7 years. PCDTBT surpasses the performance of P3HT (the most studied polymeric material until now) and is now considered as one of the new benchmarks for the development of highly efficient BHJ solar cells.