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- Chen, Haiyang, et al.
(författare)
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Heterogeneous Nucleating Agent for High-Boiling-Point Nonhalogenated Solvent-Processed Organic Solar Cells and Modules
- 2024
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Ingår i: Advanced Materials. - : WILEY-V C H VERLAG GMBH. - 0935-9648 .- 1521-4095.
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Tidskriftsartikel (refereegranskat)abstract
- High-boiling-point nonhalogenated solvents are superior solvents to produce large-area organic solar cells (OSCs) in industry because of their wide processing window and low toxicity; while, these solvents with slow evaporation kinetics will lead excessive aggregation of state-of-the-art small molecule acceptors (e.g. L8-BO), delivering serious efficiency losses. Here, a heterogeneous nucleating agent strategy is developed by grafting oligo (ethylene glycol) side-chains on L8-BO (BTO-BO). The formation energy of the obtained BTO-BO; while, changing from liquid in a solvent to a crystalline phase, is lower than that of L8-BO irrespective of the solvent type. When BTO-BO is added as the third component into the active layer (e.g. PM6:L8-BO), it easily assembles to form numerous seed crystals, which serve as nucleation sites to trigger heterogeneous nucleation and increase nucleation density of L8-BO through strong hydrogen bonding interactions even in high-boiling-point nonhalogenated solvents. Therefore, it can effectively suppress excessive aggregation during growth, achieving ideal phase-separation active layer with small domain sizes and high crystallinity. The resultant toluene-processed OSCs exhibit a record power conversion efficiency (PCE) of 19.42% (certificated 19.12%) with excellent operational stability. The strategy also has superior advantages in large-scale devices, showing a 15.03-cm2 module with a record PCE of 16.35% (certificated 15.97%). The heterogeneous nucleating agent (BTO-BO) is developed to suppress the excessive aggregation of L8-BO in high-boiling-point nonhalogenated solvents processing, achieving the active layer with high crystallinity and nano-scaled phase separation morphology. The resultant OSCs achieve record power conversion efficiencies of 19.42% (0.062-cm2) and 16.35% (15. 03-cm2) with excellent operational stabilities. image
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| 2. |
- Zhang, Ben, et al.
(författare)
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Rapid solidification for green-solvent-processed large-area organic solar modules with >16% efficiency
- 2024
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Ingår i: Energy & Environmental Science. - : ROYAL SOC CHEMISTRY. - 1754-5692 .- 1754-5706.
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Tidskriftsartikel (refereegranskat)abstract
- Enabling green-solvent-processed large-area organic solar cells (OSCs) is of great significance to their industrialization. However, precisely controlling the temperature-dependent fluid mechanics and evaporation behavior of green solvents with high-boiling points is challenging. Controlling these parameters is essential to prevent the non-uniform distribution of active layer components and severe molecule aggregation, which collectively degrade the power conversion efficiency (PCE) of large-scale devices. In this study, we revealed that the temperature gradient distribution across a wet film is the root of the notorious Marangoni effect, which leads to the formation of a severely non-uniform active layer on a large scale. Thus, a rapid solidification strategy was proposed to accelerate the evaporation of toluene, a green solvent, at room temperature. This strategy simultaneously inhibits the Marangoni effect and suppresses molecular aggregation in the wet film, allowing the formation of a nano-scale phase separation active layer with uniform morphology. The resultant toluene-processed 15.64-cm2 large-area OSC module achieves an outstanding PCE of 16.03% (certified: 15.69%), which represents the highest reported PCE of green-solvent-processed OSC modules. Notably, this strategy also exhibits a weak scale dependence on the PCE, and we successfully achieved a state-of-the-art PCE of 14.45% for a 72.00-cm2 OSC module. A rapid solidification strategy was developed for simultaneously avoiding the Marangoni effect and suppressing molecular aggregation. The resultant 15.64 cm2 large-area OSC module exhibited a record power conversion efficiency of 16.03%.
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