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Double‐cable conjugated polymers with near‐infrared (NIR) electron acceptors are synthesized for use in single‐component organic solar cells (SCOSCs). Through the development of a judicious synthetic pathway, the highly sensitive nature of the 2‐(3‐oxo‐2,3‐dihydroinden‐1‐ylidene)malononitrile (IC)‐based electron acceptors in basic and protonic solvents is overcome. In addition, an asymmetric design motif is adopted to optimize the packing of donor and acceptor segments, enhancing charge separation efficiency. As such, the new double‐cable polymers are successfully applied in SCOSCs, providing an efficiency of over 10 % with a broad photo response from 300 to 850 nm and exhibiting excellent thermal/light stability. These results demonstrate the powerful design of NIR‐acceptor‐based double‐cable polymers and will enable SCOSCs to enter a new stage. [ABSTRACT FROM AUTHOR]

We developed a series of highly crystalline double‐cable conjugated polymers for application in single‐component organic solar cells (SCOSCs). These polymers contain conjugated backbones as electron donor and pendant perylene bisimide units (PBIs) as electron acceptor. PBIs are connected to the backbone via alkyl units varying from hexyl (C6H12) to eicosyl (C20H40) as flexible linkers. For double‐cable polymers with short linkers, the PBIs tend to stack in a head‐to‐head fashion, resulting in large d‐spacings (e.g. 64 Å for the polymer P12 with C12H24 linker) along the lamellar stacking direction. When the length of the linker groups is longer than a certain length, the PBIs instead adopt a more ordered packing likely via H‐aggregation, resulting in short d‐spacings (e.g. 50 Å for the polymer P16 with C16H32 linker). This work highlights the importance of linker length on the molecular packing of the acceptor units and the influences on the photovoltaic performance of SCOSCs. [ABSTRACT FROM AUTHOR]

A record power conversion efficiency of 8.40 % was obtained in single‐component organic solar cells (SCOSCs) based on double‐cable conjugated polymers. This is realized based on exciton separation playing the same role as charge transport in SCOSCs. Two double‐cable conjugated polymers were designed with almost identical conjugated backbones and electron‐withdrawing side units, but extra Cl atoms had different positions on the conjugated backbones. When Cl atoms were positioned at the main chains, the polymer formed the twist backbones, enabling better miscibility with the naphthalene diimide side units. This improves the interface contact between conjugated backbones and side units, resulting in efficient conversion of excitons into free charges. These findings reveal the importance of charge generation process in SCOSCs and suggest a strategy to improve this process: controlling miscibility between conjugated backbones and aromatic side units in double‐cable conjugated polymers. [ABSTRACT FROM AUTHOR]

The crystalline cooperativity of the donor and acceptor segment in double‐cable conjugated polymers plays an important role in the nanophase separation and photovoltaic performance in single‐component organic solar cells (SCOSCs). Two double‐cable conjugated polymers with the same conjugated backbone and perylene bisimide (PBI) side units were designed in which PBIs were positioned symmetrically and perpendicularly (P1) and asymmetrically and slantingly (P2) along the conjugated backbones. After thermal annealing, both conjugated backbones and PBI side units in P1 tend to form ordered nanostructures, while PBI side units in P2 dominated the crystallization and hamper the crystallization of conjugated backbones. P1 showed good crystalline cooperativity between conjugated backbones and PBI side units, resulting in improved power conversion efficiencies (PCEs) up to 3.43 % in SCOSCs, while P2 with poor crystalline cooperativity exhibited PCEs below 2.42 %. [ABSTRACT FROM AUTHOR]

A series of conjugated polymers containing benzodithiophene as donor and isoindigo as acceptor with no, one, two and three thiophene spacer groups is synthesized and characterized. The polymer with bithiophene as a spacer has a superior efficiency of 7.31% in solar cells. This demonstrates an important design strategy to produce polymers for high‐performance solar cells by inserting thiophene spacer groups. [ABSTRACT FROM AUTHOR]

Semi-transparent (ST) organic solar cells with potential application as power generating windows are studied. The main challenge is to find proper transparent electrodes with desired electrical and optical properties. In this work, this is addressed by employing an amphiphilic conjugated polymer PFPA-1 modified ITO coated glass substrate as the ohmic electron-collecting cathode and PEDOT:PSS PH1000 as the hole-collecting anode. For active layers based on different donor polymers, considerably lower reflection and parasitic absorption are found in the ST solar cells as compared to solar cells in the standard geometry with an ITO/PEDOT:PSS anode and a LiF/Al cathode. The ST solar cells have remarkably high internal quantum efficiency at short circuit condition (∼90%) and high transmittance (∼50%). Hence, efficient ST tandem solar cells with enhanced power conversion efficiency ( PCE) compared to a single ST solar cell can be constructed by connecting the stacked two ST sub-cells in parallel. The total loss of photons by reflection, parasitic absorption and transmission in the ST tandem solar cell can be smaller than the loss in a standard solar cell based on the same active materials. We demonstrate this by stacking five separately prepared ST cells on top of each other, to obtain a higher photocurrent than in an optimized standard solar cell. [ABSTRACT FROM AUTHOR]

[Display omitted] • S, N and O atoms are used for stepwise and fine regulation of the band structure and electron-transfer of photocatalysts. • COP-S shows dramatically promoted charge transfer and separation. • The energy barrier for CO 2 activation and conversion on COP-S are decreased. • The H 2 O oxidization to O 2 are achieved with the single COP-S. The atom refining strategy is used for the design of COP-X (X = S, N, O) as the efficient photocatalysts for CO 2 conversion. Both photoelectrochemical experiments and computational explorations demonstrate that the electron delocalization and reaction barrier can be well regulated by single atom substitution of S, N and O in the 1,3,5-triethynylbenzene linked COPs. Based on the prominent electron donating capacity of S, the fast electron transfer and prolonged lifetime of photoinduced charge carriers endow COP-S with superior photocatalytic CO 2 conversion efficiency and selectivity. The CO production rate reaches 196.4 μmol g-1h−1 without the presence of cocatalysts and sacrificial agents, which is 2.1-folds and 2.5-folds of COP-N and COP-O. In particular, the oxidization of H 2 O to O 2 is also realized on bulk COP-S. Our explorations expand the COPs skeleton engineering toolbox and provide new guidance for the design of efficient catalysts for solar energy utilizations. [ABSTRACT FROM AUTHOR]