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1. Robust Molecular Dipole‐Enabled Defect Passivation and Control of Energy‐Level Alignment for High‐Efficiency Perovskite Solar Cells

   https://doi.org/10.1002/anie.202105512  

   Wang, Bing; Li, Hong; Dai, Qingqing; Zhang, Meng; Zou, Zhigang; Brédas, Jean‐Luc; Lin, Zhiqun (June 2021, Angewandte Chemie International Edition)

   Abstract The ability to passivate defects and modulate the interface energy‐level alignment (IEA) is key to boost the performance of perovskite solar cells (PSCs). Herein, we report a robust route that simultaneously allows defect passivation and reduced energy difference between perovskite and hole transport layer (HTL) via the judicious placement of polar chlorine‐terminated silane molecules at the interface. Density functional theory (DFT) points to effective passivation of the halide vacancies on perovskite surface by the silane chlorine atoms. An integrated experimental and DFT study demonstrates that the dipole layer formed by the silane molecules decreases the perovskite work function, imparting an Ohmic character to the perovskite/HTL contact. The corresponding PSCs manifest a nearly 20 % increase in power conversion efficiency over pristine devices and a markedly enhanced device stability. As such, the use of polar molecules to passivate defects and tailor the IEA in PSCs presents a promising platform to advance the performance of PSCs. 

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2. Cosolvent incorporation modulates the thermal and structural response of PNIPAM/silyl methacrylate copolymers

   https://doi.org/10.1039/D4SM00246F  

   Linn, Jason D.; Rodriguez, Fabian A.; Calabrese, Michelle A. (April 2024, Soft Matter)

   The nanoscale structure formation and optical response of aqueous thermoresponsive polymers with reactive silane groups can be widely tunedviapolymer architecture and organic cosolvent incorporation. 

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3. Microwave Assisted Sol-Gel Synthesis of Silica-Spider Silk Composites

   https://doi.org/10.3390/molecules24142521  

   Giasuddin, Abul Bashar; Britt, David W. (July 2019, Molecules)

   This study introduces a simple and environmentally friendly method to synthesize silica-protein nanocomposite materials using microwave energy to solubilize hydrophobic protein in an aqueous solution of pre-hydrolyzed organo- or fluoro-silane. Sol-gel functionality can be enhanced through biomacromolecule incorporation to tune mechanical properties, surface energy, and biocompatibility. Here, synthetic spider silk protein and organo- and fluoro-silane precursors were dissolved and mixed in weakly acidic aqueous solution using microwave technology. Scanning electron microscopy (SEM) and Atomic force microscopy (AFM) images revealed the formation of spherical nanoparticles with sizes ranging from 100 to 500 nm depending, in part, on silane fluoro- or organo-side chain chemistry. The silane-protein interaction in the nanocomposite was assessed through infrared spectroscopy. Deconvoluted ATR-FTIR (Attenuated total reflectance Fourier-transform infrared spectroscopy) spectra revealed silane chemistry-specific conformational changes in the protein-silane nanocomposites. Relative to microwave-solubilized spider silk protein, the β structure content increased by 14% in the spider silk-organo-silica nanocomposites, but decreased by a net 20% in the spider silk-fluoro-silica nanocomposites. Methods of tuning the secondary structures, and in particular β-sheets that are the cross-linking moieties in spider silks and other self-assembling fibrillar proteins, may provide a unique means to promote protein interactions, favor subsequent epitaxial growth process, and enhance the properties of the protein-silane nanocomposites. 

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4. Unusual nucleophilic reactivity of a dithiolene-based N-heterocyclic silane

   https://doi.org/10.1039/d3dt03843b  

   Tran, Phuong M; Wang, Yuzhong; Lahm, Mitchell E; Wei, Pingrong; Schaefer, Henry F; Robinson, Gregory H (April 2024, Dalton Transactions)

   Dithiolene-based N-heterocyclic silane demonstrates unusual dual nucleophilic reactivity toward boron halides. 

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5. Tellurorhodamine photocatalyzed aerobic oxidation of organo-silanes and phosphines by visible-light

   https://doi.org/10.1039/C9DT00487D  

   Rettig, Irving D.; Van, Jackson; Brauer, Jacob B.; Luo, Wentai; McCormick, Theresa M. (April 2019, Dalton Transactions)

   Tellurorhodamine, 9-mesityl-3,6-bis(dimethylamino)telluroxanthylium hexafluorophosphate ( 1 ), photocatalytically oxidizes aromatic and aliphatic silanes and triphenyl phosphine under mild aerobic conditions. Under irradiation with visible light, 1 can react with self-sensitized 1 O 2 to generate the active telluroxide oxidant ( 2 ). Silanes are oxidized to silanols and triphenyl phosphine is oxidized to triphenyl phoshine oxide either using 2 , or 1 with aerobic irradiation. Kinetic experiments coupled with a computational study elucidate possible mechanisms of oxidation for both silane and phosphine substrates. First-order rates were observed in the oxidation of triphenyl phosphine and methyldiphenyl silane, indicating a substitution like mechanism for substrate binding to the oxidized tellurium( iv ). Additionally, these reactions exhibited a rate-dependence on water. Oxidations were typically run in 50 : 50 water/methanol, however, the absence of water decreased the rates of silane oxidation to a greater degree than triphenyl phosphine oxidation. Parallel results were observed in solvent kinetic isotope experiments using D 2 O in the solvent mixture. The rates of oxidation were slowed to a greater degree in silane oxidation by 2 ( k H / k D = 17.30) than for phosphine ( k H / k D = 6.20). Various silanes and triphenyl phosphine were photocatalytically oxidized with 1 (5%) under irradiation with warm white LEDs using atmospheric oxygen as the terminal oxidant. 

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