Boosting the Fill Factor through Sequential Deposition and Homo Hydrocarbon Solvent toward Efficient and Stable All‐Polymer Solar Cells

Abstract

All‐polymer solar cells (all‐PSCs) have achieved impressive progress in photovoltaic performance and stabilities recently. However, their power conversion efficiencies (PCEs) still trail that of small‐molecular acceptor‐based organic solar cells (>19%) mainly because of the inferior fill factor (FF). Herein, a combined homo hydrocarbon solvent and sequential deposition (SD) strategy is presented to boost the FF of rigid all‐PSCs to 77.7% and achieve a superior PCE of 17.7% with excellent stability, which is among the highest efficiencies reported for all‐PSCs thus far. Meanwhile, a remarkable PCE of 14.5% is realized for flexible all‐PSCs with outstanding mechanical stability. The blend film morphologies measurements suggest that the SD method enables the formation of an ideal pseudo‐bilayer film with bicontinuous interdigitated structure and ordered polymer packing. The numerical simulation result indicates that the FF enhancement mainly results from the efficient exciton diffusion dynamics, increased carrier mobilities, and more balanced electron/hole mobility ratio induced by the developed SD method. This is also confirmed by the FF loss analysis, which manifests that the reduced series resistance and increased shunt resistance are the main reasons for the reduction of FF loss. This work provides a promising strategy to fabricate highly efficient and stable all‐PSCs to promote their future development and practical manufacturing.

Improved photovoltaic performance and robustness of all-polymer solar cells enabled by a polyfullerene guest acceptor

“…2a , and the corresponding photovoltaic parameters of three groups of all-PSCs are summarized in Table 1 . By constructing a pseudo-bilayer architecture 50 – 52 , the PCEs of both ternary cells increase compared to the binary system (Fig. 2b ).…”

Recent Strategies for High-Performing Indoor Perovskite Photovoltaics

“…Thus, another strategy is to prevent any Pb leakage from Pb-based Id-PPVs through encapsulation. There are various encapsulation materials and techniques, such as organic polymers with hydrophobicity and flexibility [ 96 , 97 , 98 ], inorganic materials with high stability from environmental stimuli [ 99 , 100 , 101 ], carbon-based materials exhibiting good optical and mechanical properties [ 102 ], multi-layer/composition of hybrid encapsulation [ 103 , 104 , 105 , 106 , 107 ], and Pb absorbents within PPVs [ 108 , 109 , 110 ]. However, materials and structures for advanced encapsulation still need further development to prevent Pb leakage during practical use.…”

High-Performance Pseudo-Bilayer Organic Solar Cells Enabled by Sequential Deposition of D18/Y6 Chloroform Solution

“…By adding an asymmetric electron–acceptor BTP-S2 into PM6/BO-4Cl, Chen and co-workers fabricated a ternary LbL solar cell using the same CF solvent for the two layers, achieved reduced charge recombination, promoted charge collection, enhanced the photocurrent and fill factor in LbL-type ternary OPVs, and materialized 18.16% efficiency in the ternary device . Zhu et al applied ortho -xylene (o-XY) as the solvent to fabricate PM6:PY-V-γ-based all-polymer solar cells and achieved a champion PCE of 17.7% and high fill factor of 77.7% with excellent stability, while the efficiency of the BHJ device was 16.6% . Li et.al used the CF prepared PM6/Y6-based LbL device and added PC 71 BM as the third component to the Y6 layer, which effectuated 17.82% efficiency in contrast to that of the 17.09% of the PM6:Y6:PC 71 BM-based BHJ device .…”

“…30 Zhu et al applied ortho-xylene (o-XY) as the solvent to fabricate PM6:PY-V-γ-based all-polymer solar cells and achieved a champion PCE of 17.7% and high fill factor of 77.7% with excellent stability, while the efficiency of the BHJ device was 16.6%. 31 Li et.al used the CF prepared PM6/Y6based LbL device and added PC 71 BM as the third component to the Y6 layer, which effectuated 17.82% efficiency in contrast to that of the 17.09% of the PM6:Y6:PC 71 BM-based BHJ device. 32 Wei et al used CF as the solvent to prepare the D18/ Y1/Y6-based semitransparent tri-heterojunction solar cell through the SD approach, attaining a PCE of 13.5% at an average visible transmittance (AVT) of 23.8% with color rendering properties quantifying a light transmission capacity (CRI) of 85.…”