Layer-by-Layer All-Polymer Solar Cells Approaching 19% with Dual-Donor Modulation of an Interpenetrating Network

All-polymer systems are promising for commercial applications because the lower diffusivity of polymers helps to inhibit the large-scaled phase separation and obtain excellent stability. Achieving a fine-tuned morphology of the active layer with an appropriate vertical phase has long been a major goal in obtaining efficient all-polymer solar cells (all-PSCs). Herein, through the synergistic effect of layer-by-layer (LBL) structure and dual donor strategy, high performance and stable all-PSCs are prepared by constructing an interpenetrating network. The introduction of the third component PTzBI-dF suppresses excessive aggregation and reduces exciton recombination. The formation of a favorable p-i-n structure helps to adjust the vertical phase distribution and improve stability. Ultimately, through the fine optimization, PBQx-T-Cl:PTzBI-dF/PY-IT achieves a high PCE of 18.83%. This research demonstrates a simple and effective way to construct high-performance OSCs by desirable active layer morphology and vertical phase distribution.