Over 17.1% or 18.2% Efficiency of Layer-by-Layer All-Polymer Solar Cells via Incorporating Efficient Pt Complexes as Energy Donor Additive

Layer-by-layer (LbL) all-polymer solar cells (APSCs) are constructed with or without the incorporation of a Pt complex F-Pt as an energy donor additive in the acceptor layer. The power conversion efficiency (PCE) of LbL APSCs can be enhanced from 15.86% to 17.14% through introducing 0.2 wt % F-Pt in the PY-IT layer, originating from the efficient energy transfer from F-Pt to PM6 and PY-IT. The efficient energy transfer from F-Pt to PM6 and PY-IT can be well confirmed from the spectral overlapping between photoluminescence (PL) spectra of F-Pt and absorption spectra of PM6 and PY-IT, as well as the prolonged PL lifetime of PM6 and PY-IT according to the transient time-resolved PL spectra of blend and LbL films. The universality of the F-Pt incorporation strategy can be further confirmed from PBQx-TCl/PY-DT based LbL APSCs, and PCE can be increased from 17.57% to 18.29% by incorporating F-Pt into the PY-DT layer.