Procedures for Increasing the Efficiency of Polymeric P3HT:PCBM Solar Cells

In the past decades, the solar cells based on regioregular poly(3-hexylthiophene) (P3HT) and phenyl-C-butyric acid methyl ester (PCBM) have attracted a large attention among the polymeric photovoltaics. Although the P3HT:PCBM solar cells possess some advantages such as low-weight, low-cost and flexibility, their power conversion efficiency (PCE) is relatively less than other types of photovoltaic systems. Thereby, the researchers from various fields have focused on different methodologies to increase the PCE by manipulating the active layer morphology, which plays a substantial role in the efficacy of polymeric solar cells. A morphology with the pure phase separated donor (P3HT) and acceptor (PCBM) components which are connected to each other is an optimized morphology. The solar cells demand the pathways of interconnected donors and acceptors to reach an appropriate function, which could be originated from the crystallization and nanoscale phase separation in the active layer. This work is devoted to review the effective procedures to enhance the PCE of P3HT:PCBM photovoltaics including preparation and annealing methods, use of distinct polymeric and non-polymeric additives, some particular methods such as developing the core-shell nanofibers and nanospheres and anodic patterns as well as controlling the crystallinity and orientation of the donor chains.