We report design principles of the thermal and redox properties of synthetically accessible spiro-based hole transport materials (HTMs) and show the relevance of these findings to high-performance perovskite solar cells (PSCs). The chemical modification of an asymmetric spiro[fluorene-9,9'-xanthene] core is amenable to selective placement of redox active triphenylamine (TPA) units. We therefore leveraged computational techniques to investigate five HTMs bearing TPA groups judiciously positioned about this asymmetric spiro core. It was determined that TPA groups positioned about the conjugated fluorene moiety increase the free energy change for hole-extraction from the perovskite layer, while TPAs about the xanthene unit govern the T values. The synergistic effects of these characteristics resulted in an HTM characterized by both a low reduction potential (≈0.7 V vs. NHE) and a high T value (>125 °C) to yield a device power conversion efficiency (PCE) of 20.8 % in a PSC.
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http://dx.doi.org/10.1002/anie.201810809 | DOI Listing |
J Am Chem Soc
January 2025
State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou 350108, China.
Oxygen vacancies (OVs) spatially confined on the surface of metal oxide semiconductors are advantageous for photocatalysis, in particular, for O-involved redox reactions. However, the thermal annealing process used to generate surface OVs often results in undesired bulk OVs within the metal oxides. Herein, a high pressure-assisted thermal annealing strategy has been developed for selectively confining desirable amounts of OVs on the surface of metal oxides, such as tungsten oxide (WO).
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Institute of Chemistry Chinese Academy of Sciences, CAS Key Laboratory of Molecular Recognition and Function, CHINA.
A pair of axially chiral thermally activated delayed fluorescent (TADF) enantiomers, R-TCBN-ImEtPF6 and S-TCBN-ImEtPF6, with intrinsic ionic characteristics were efficiently synthesized by introducing imidazolium hexafluorophosphate to chiral TADF unit. The TADF imidazolium salts exhibited a high photoluminescence quantum yield (PLQY) of up to 92%, a small singlet-triplet energy gap (∆EST) of 0.04 eV, as well as reversible redox properties.
View Article and Find Full Text PDFCancers (Basel)
January 2025
Department of Dermatology and Venerology, Rostock University Medical Center, Strempelstr. 13, 18057 Rostock, Germany.
Oxidative stress is universal to all cell types, including cancer. It is elicited by a surplus of reactive oxygen species (ROS) or a reduced cellular ability to defend against those. At low levels (oxidative eustress), this induces altered cellular signaling, while at higher levels (oxidative distress), cellular toxicity and non-specific redox signaling become apparent.
View Article and Find Full Text PDFSci Total Environ
January 2025
Department of Geography, Royal Holloway University of London, Surrey, UK.
Future climate projections are expected to have a substantial impact on boreal lake circulation regimes. Understanding lake sensitivity to warmer climates is therefore critical for mitigating potential ecological and societal impacts. The Holocene Thermal Maximum (HTM; ca 7-5 ka BP) provides a valuable analogue to investigate lake responses to warmer climates devoid of major anthropogenic influences.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
National Engineering Research Center for Biomaterials, College of Biomedical Engineering, Sichuan University, Chengdu, 610064, China.
MXenzymes, a promising class of catalytic therapeutic material, offer great potential for tumor treatment, but they encounter significant obstacles due to suboptimal catalytic efficiency and kinetics in the tumor microenvironment (TME). Herein, this study draws inspiration from the electronic structure of transition metal vanadium, proposing the leverage of TME specific-features to induce structural transformations in sheet-like vanadium carbide MXenzymes (TVMz). These transformations trigger cascading catalytic reactions that amplify oxidative stress, thereby significantly enhancing multimodal tumor therapy.
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