| 1. |
- Ji, Jingjing, et al.
(författare)
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Developing Halogen-Free Polymer Donors for Efficient Nonfullerene Organic Solar Cells by Addition of Highly Electron-Deficient Diketopyrrolopyrrole Unit
- 2021
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Ingår i: Solar RRL. - : Wiley. - 2367-198X. ; 5:5
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Tidskriftsartikel (refereegranskat)abstract
- High-performance polymer donors when paired with nonfullerene acceptors are mainly limited to flanking halogenated benzodithiophene (BDT)-based π-conjugated copolymers, which however involve complex synthetic procedures. Herein, a series of halogen-free polymer donors that link BDT moiety with two highly electron-deficient benzodithiophene-dione (BDD) and diketopyrrolopyrrole (DPP) units with various molar ratios is developed. Compared with the benchmark PBDB-T donor containing BDD unit, additional incorporation of a stronger electron-negative DPP unit markedly lowers frontier molecular orbital levels and extends optical absorption, potentially leading to simultaneously enhanced VOC and JSC in organic solar cells. A remarkable power conversion efficiency (PCE) of 10.28% is thus obtained in the optimal P75 (BDD : DPP = 3:1 mol%) and Y6 blend cells in comparison with the reference PBDB-T:Y6 (9.20%). A slight addition of PC71BM into the blend is found to further generate finer phase-separated domains and thus increase the best efficiency up to 12.20%. The subtly critical roles of PC71BM are determined by transient absorption measurements on both thin-film and in situ devices to be the prolonged free charge carrier lifetime and the shallow charge transfer states, which enhance JSC and fill factor in the device, respectively.
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| 2. |
- Yang, Jinglun, et al.
(författare)
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Robust and Large-Area Calix[4]pyrrole-Based Nanofilms Enabled by Air/DMSO Interfacial Self-Assembly-Confined Synthesis
- 2021
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society. - 1944-8244 .- 1944-8252. ; 13:2, s. 3336-3348
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Tidskriftsartikel (refereegranskat)abstract
- The modular construction of defect-free nanofilms with a large area remains a challenge. Herein, we present a scalable strategy for the preparation of calix[4]pyrrole (C[4]P)-based nanofilms through acryl hydrazone reaction conducted in a tetrahydrazide calix[4]pyrrole (CPTH)-based self-assembled layer at the air/DMSO interface. With this strategy, robust, regenerable, and defect-free nanofilms with an exceptionally large area (?750 cm2) were constructed. The thickness and permeability of the film systems can be fine-tuned by varying the precursor concentration or by changing another building block. A typical nanofilm (C[4]P-TFB, ?67 nm) depicted high water flux (39.9 L m-2 h-1 under 1 M Na2SO4), narrow molecular weight cut-off value (?200 Da), and promising antifouling properties in the forward osmosis (FO) process. In addition, the nanofilms are stable over a wide pH range and tolerable to different organic solvents. Interestingly, the introduction of C[4]P endowed the nanofilms with both outstanding mechanical properties and unique group-selective separation capability, laying the foundation for wastewater treatment and pharmaceutical concentration.
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