Fused‐ring induced end‐on orientation in conjugated molecular dyads toward efficient single‐component organic solar cells

Abstract

The molecular orientations of conjugated materials on the substrate mainly include edge-on, face-on, and end-on. Edge-on and face-on orientations have been widely observed, while end-on orientation has been rarely reported. Since in organic solar cells (OSCs) charge transport is along the vertical direction, end-on orientation with conjugated backbones perpendicular to the substrate is recognized as the ideal microstructure for OSCs. In this work, we for the first time obtained the preferential end-on orientation in a conjugated molecular dyad that contains a conjugated backbone as donor and perylene bisimide side units as acceptor. This was realized by introducing a fused-ring structure to replace linear terthiophenes with conjugated backbones, yielding F-MDPBI and L-MDPBI respectively. Surprisingly, a shifting trend of the molecular orientation from dominating edge-on in L-MDPBI to preferential end-on in F-MDPBI was observed. As a consequence, vertical charge carrier mobilities in F-MDPBI are one order of magnitude higher than those with preferential edge-on orientation, so single-component OSCs based on this molecular dyad as a single photoactive layer provided a power conversion efficiency of 4.89% compared to 1.70% based on L-MDPBI with preferential edge-on orientation. K E Y W O R D Sconjugated molecular dyads, crystallinity, edge-on, end-on, single-component organic solar cells INTRODUCTIONBulk-heterojunction organic solar cells (BHJOSCs) with electron donors and acceptors in the photoactive layer haveThis is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Ferrocene‐Terminated Perylene Diimide‐Based Small Molecular Electrolyte as Electron‐Transport Layer for Efficient Organic Solar Cells

“…These bands arise from the 0 to 0 and 0 to 1 electronic transitions of the PDI moiety, respectively. [ 44–48 ] Notably, PDIN and PDIN‐Fc present analogous absorption profiles. However, PDIN‐Fc demonstrates the increased intensity of these two absorption bands in solution, accompanied by a broader absorption profile.…”

All-polymer solar cells based on wide bandgap polymerized non-fused electron acceptors for indoor photovoltaics

“…The comparatively higher intensities of the 0-0/0-1 peaks for WP1-3 provide evidence of characteristic J-aggregation behavior both in solution and thin film states, as previously documented in the literature. 31,32 Moreover, all the spectra of these polymers exhibit typical blue shifts in turn when increasing the temperatures from 30 1C to 90 1C, and these blue shifts become saturated at 120 1C (Fig. S3, ESI †).…”

Incorporating Naphthalene and Halogen into Near-Infrared Double-Cable Conjugated Polymers for Single-Component Organic Solar Cells with Low-Voltage Losses

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