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Creators/Authors contains: "Herrera, Christopher_K"

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  1. Abstract Photodynamic therapy (PDT) is currently limited by the inability of photosensitizers (PSs) to enter cancer cells and generate sufficient reactive oxygen species. Utilizing phosphorescent triplet states of novel PSs to generate singlet oxygen offers exciting possibilities for PDT. Here, we report phosphorescent octahedral molybdenum (Mo)‐based nanoclusters (NC) with tunable toxicity for PDT of cancer cells without use of rare or toxic elements. Upon irradiation with blue light, these molecules are excited to their singlet state and then undergo intersystem crossing to their triplet state. These NCs display surprising tunability between their cellular cytotoxicity and phototoxicity by modulating the apical halide ligand with a series of short chain fatty acids from trifluoroacetate to heptafluorobutyrate. The NCs are effective in PDT against breast, skin, pancreas, and colon cancer cells as well as their highly metastatic derivatives, demonstrating the robustness of these NCs in treating a wide variety of aggressive cancer cells. Furthermore, these NCs are internalized by cancer cells, remain in the lysosome, and can be modulated by the apical ligand to produce singlet oxygen. Thus, (Mo)‐based nanoclusters are an excellent platform for optimizing PSs. Our results highlight the profound impact of molecular nanocluster chemistry in PDT applications. 
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  2. Abstract Visibly transparent luminescent solar concentrators (TLSC) can optimize both power production and visible transparency by selectively harvesting the invisible portion of the solar spectrum. Since the primary applications of TLSCs include building envelopes, greenhouses, automobiles, signage, and mobile electronics, maintaining aesthetics and functionalities is as important as achieving high power conversion efficiencies (PCEs) in practical deployment. In this work, massive‐downshifting phosphorescent nanoclusters and fluorescent organic molecules are combined into a TLSC system as ultraviolet (UV) and near‐infrared (NIR) selective‐harvesting luminophores, respectively, demonstrating UV and NIR dual‐band selective‐harvesting TLSCs with PCE over 3%, average visible transmittance (AVT) exceeding 75% and color metrics suitable for the window industry. With distinct wavelength‐selectivity and effective utilization of the invisible portion of the solar spectrum, this work reports the highest light utilization efficiency (PCE × AVT) of 2.6 for a TLSC system, the highest PCE of any transparent photovoltaic (TPV) devices with AVT greater than 70%, and outperforms the practical limit for non‐wavelength‐selective TPV. 
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