Enhanced and Balanced Charge Transport Boosting Ternary Solar Cells Over 17% Efficiency

Abstract

Ternary architecture is one of the most effective strategies to boost the power conversion efficiency (PCE) of organic solar cells (OSCs). Here, an OSC with a ternary architecture featuring a highly crystalline molecular donor DRTB‐T‐C4 as a third component to the host binary system consisting of a polymer donor PM6 and a nonfullerene acceptor Y6 is reported. The third component is used to achieve enhanced and balanced charge transport, contributing to an improved fill factor (FF) of 0.813 and yielding an impressive PCE of 17.13%. The heterojunctions are designed using so‐called pinning energies to promote exciton separation and reduce recombination loss. In addition, the preferential location of DRTB‐T‐C4 at the interface between PM6 and Y6 plays an important role in optimizing the morphology of the active layer.

Suppressing Kinetic Aggregation of Non‐Fullerene Acceptor via Versatile Alloy States Enables High‐Efficiency and Stable Ternary Polymer Solar Cells

“…The parameters of surface energy (γ) are calculated to be 34.6, 29.9, 26.7, and 36.1 mN m –1 for PM6, BTP‐4Cl, PDI‐2T, and DRCN5T (Table S1, Supporting Information), respectively, suggesting PDI‐2T with the smallest γ prefers to concentrate on the top of ternary active layer while DRCN5T with the largest γ is likely to be located at the bottom of the ternary blend. [ 41 ] Moreover, the accurate distribution of the third component is further estimated by the Flory–Huggins interaction parameter χ (Table S1, Supporting Information). [ 42 ] The smaller χ values of 0.091 and 0.016 for PDI‐2T:BTP‐4Cl and DRCN5T:PM6 with respect to those of PDI‐2T:PM6 (0.511) and DRCN5T:BTP‐4Cl (0.292) validate the better compatibility between two electron acceptors as well as two electron donors, [ 26,43 ] which is very conducive to constructing the alloy states in the acceptor and donor phase.…”

Achieving Efficient Ternary Organic Solar Cells Using Structurally Similar Non‐Fullerene Acceptors with Varying Flanking Side Chains

“…On the other side, ternary OSCs have been demonstrated to be one of the effective methods to further optimize device performance by the addition of a guest component. [ 45–59 ] So far, the best‐performing PTQ10‐based ternary devices have mainly relied on fullerene derivatives as the guest acceptor to form hierarchical blend morphology to promote short‐circuit current density ( J SC ) and fill factor (FF). [ 60,61 ] But typical fullerene derivatives have large surface energy, which makes it challenging to predict the morphological compatibility, namely the molecular interactions, between the fullerene and the host donor/acceptor components.…”

Side‐Chain Engineering on Y‐Series Acceptors with Chlorinated End Groups Enables High‐Performance Organic Solar Cells

“…[9][10][11][12][13][14][15][16][17][18][19] Among them, the emerging Y-series acceptors exhibit excellent optoelectronic properties and contribute to excellent photovoltaic performances of over 17%. [20][21][22][23][24][25][26][27][28][29] Therefore, it is important to understand the structureproperty relationships of Y-series acceptors and figure out effective methods to further optimize their chemical structures.…”