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Functionalization of Si‐bound methyl group provides an efficient access to diverse organosilanes. However, the asymmetric construction of silicon‐stereogenic architectures by functionalization of Si‐bound methyl group has not yet been described despite recent significant progress in producing chiral silicon. Herein, we disclosed the enantioselective silylmethyl functionalization involving the aryl to alkyl 1,5‐palladium migration to access diverse naphthalenes possessing an enantioenriched stereogenic silicon center, which are inaccessible before. It is worthy to note that the realization of asymmetric induction at the step of metal migration itself remains challenging. Our study constitutes the first enantioselective aryl to alkyl 1,5‐palladium migration reaction. The key to the success is the discovery and fine‐tuning of the different substituents of α,α,α,α‐tetraaryl‐1,3‐dioxolane‐4,5‐dimethanol (TADDOL)‐based phosphoramidites, which ensure the enantioselectivity and desired reactivity. [ABSTRACT FROM AUTHOR]

Halide solid electrolytes (SEs) have attracted significant attention due to their competitive ionic conductivity and good electrochemical stability. Among typical halide SEs (chlorides, bromides, and iodides), substantial efforts have been dedicated to chlorides or bromides, with iodide SEs receiving less attention. Nevertheless, compared with chlorides or bromides, iodides have both a softer Li sublattice and lower reduction limit, which enable iodides to possess potentially high ionic conductivity and intrinsic anti‐reduction stability, respectively. Herein, we report a new series of iodide SEs: LixYI3+x (x=2, 3, 4, or 9). Through synchrotron X‐ray/neutron diffraction characterizations and theoretical calculations, we revealed that the LixYI3+x SEs belong to the high‐symmetry cubic structure, and can accommodate abundant vacancies. By manipulating the defects in the iodide structure, balanced Li‐ion concentration and generated vacancies enables an optimized ionic conductivity of 1.04 × 10−3 S cm−1 at 25 °C for Li4YI7. Additionally, the promising Li‐metal compatibility of Li4YI7 is demonstrated via electrochemical characterizations (particularly all‐solid‐state Li‐S batteries) combined with interface molecular dynamics simulations. Our study on iodide SEs provides deep insights into the relation between high‐symmetry halide structures and ionic conduction, which can inspire future efforts to revitalize halide SEs. [ABSTRACT FROM AUTHOR]

It is commonly believed that the spontaneous p‐doping in Sn‐based perovskites is caused by Sn vacancies. By performing rigorous first‐principles calculations for a prototypical Sn‐based perovskite CsSnI3, we reveal that, in fact, the defects dominating p‐doping are Cs vacancies. The reason that adding extra Sn2+ could reduce p‐doping is that Cs and Sn present the same changing trend in terms of chemical potentials, and thus inhibiting the formation of Sn vacancies will also limit the formation of Cs vacancies. Moreover, we show that I vacancies are the dominant nonradiative recombination centers, and can result in sizable nonradiative losses, which explains why the experimentally measured carrier lifetime is only a few nanoseconds even if p‐doping is suppressed. This work provides new insights into the origins of p‐doping and nonradiative recombination in CsSnI3, and suggests that minimizing the formation of Cs and I vacancies is critical to realizing the best device performance. [ABSTRACT FROM AUTHOR]

It is commonly believed that the spontaneous p‐doping in Sn‐based perovskites is caused by Sn vacancies. By performing rigorous first‐principles calculations for a prototypical Sn‐based perovskite CsSnI3, we reveal that, in fact, the defects dominating p‐doping are Cs vacancies. The reason that adding extra Sn2+ could reduce p‐doping is that Cs and Sn present the same changing trend in terms of chemical potentials, and thus inhibiting the formation of Sn vacancies will also limit the formation of Cs vacancies. Moreover, we show that I vacancies are the dominant nonradiative recombination centers, and can result in sizable nonradiative losses, which explains why the experimentally measured carrier lifetime is only a few nanoseconds even if p‐doping is suppressed. This work provides new insights into the origins of p‐doping and nonradiative recombination in CsSnI3, and suggests that minimizing the formation of Cs and I vacancies is critical to realizing the best device performance. [ABSTRACT FROM AUTHOR]

Inorganic cesium lead halide perovskites offer a pathway towards thermally stable photovoltaics. However, moisture‐induced phase degradation restricts the application of hole transport layers (HTLs) with hygroscopic dopants. Dopant‐free HTLs fail to realize efficient photovoltaics due to severe electrical loss. Herein, we developed an electrical loss management strategy by manipulating poly(3‐hexylthiophene) with a small molecule, i.e., SMe‐TATPyr. The developed P3HT/SMe‐TATPyr HTL shows a three‐time increase of carrier mobility owing to breaking the long‐range ordering of "edge‐on" P3HT and inducing the formation of "face‐on" clusters, over 50 % decrease of the perovskite surface defect density, and a reduced voltage loss at the perovskite/HTL interface because of favorable energy level alignment. The CsPbI2Br perovskite solar cell demonstrates a record‐high efficiency of 16.93 % for dopant‐free HTL, and superior moisture and thermal stability by maintaining 96 % efficiency at low‐humidity condition (10–25 % R. H.) for 1500 hours and over 95 % efficiency after annealing at 85 °C for 1000 hours. [ABSTRACT FROM AUTHOR]

Abstract: A readily available small molecular hole‐transporting material (HTM), OMe‐TATPyr, was synthesized and tested in perovskite solar cells (PSCs). OMe‐TATPyr is a two‐dimensional π‐conjugated molecule with a pyrene core and four phenyl‐thiophene bridged triarylamine groups. It can be readily synthesized in gram scale with a low lab cost of around US$ 50 g−1. The incorporation of the phenyl‐thiophene units in OMe‐TATPyr are beneficial for not only carrier transportation through improved charge delocalization and intermolecular stacking, but also potential trap passivation via Pb–S interaction as supported by depth‐profiling XPS, photoluminescence, and electrochemical impedance analysis. As a result, an impressive best power conversion efficiency (PCE) of up to 20.6 % and an average PCE of 20.0 % with good stability has been achieved for mixed‐cation PSCs with OMe‐TATPyr with an area of 0.09 cm2. A device with an area of 1.08 cm2 based on OMe‐TATPyr demonstrates a PCE of 17.3 %. [ABSTRACT FROM AUTHOR]

A diruthenium complex with a redox-active amine bridge has been designed, synthesized, and studied by single-crystal X-ray analysis and DFT and TDDFT calculations. It shows three well-separated redox processes with exclusive near-infrared (NIR) absorbance at each redox state. The electropolymerized film of a related vinyl-functionalized complex displays multistate NIR electrochromism with low operational potential, good contrast ratio, and long retention time. Flip-flop, flip-flap-flop, and ternary memories have been realized by using the obtained film (ca. 15-20 nm thick) with three electrochemical inputs and three NIR optical outputs that each displays three levels of signal intensity. [ABSTRACT FROM AUTHOR]