High-Performance All-Polymer Solar Cells with a Pseudo-Bilayer Configuration Enabled by a Stepwise Optimization Strategy

In this work, an efficiency of 15.17% in the PBDB-T/PYT all-PSCs fabricated by a layer-by-layer (LbL) deposition technique is achieved by synergistically controlling additive dosages, which is not only higher than that (14.06%) of the corresponding bulk heterojunction (BHJ) device, but also the top efficient for all-PSCs. Through the studies of physical dynamics and morphological characteristics, it is found that the LbL film can effectively improve optical and electronic properties, ensure exciton separation, charge generation and extraction, reduce trap-assisted recombination, and facilitate hole transfer in LbL blends, thus achieving higher performance compared to its BHJ counterpart. Notably, the synergistic regulation of additive dosages in donor and acceptor solutions is also confirmed in the other three photovoltaic systems. Of particular note is that over 15% device performance is also achieved in the PBDB-T/PYT LbL all-PSCs fabricated via a blade-coating technique, further demonstrating the great significance of this synergistic additive-doping strategy for the printing fabrication of organic photovoltaics.

Automated summary

In this study, a high-efficiency PBDB-T/PYT all-organic solar cell was successfully fabricated using a special LbL deposition technique, achieving an efficiency of 15.17% through synergistic control of additive dosages. It was found that this synergistic control of additive dosages was also confirmed in other photovoltaic systems.