《科学》（20240802出版）一周论文导读
编译|未玖
Science, 2 AUG 2024, VOL 385, ISSUE 6708
《科学》2024年8月2日，第385卷，6708期
材料科学Materials Science
Event-responsive scanning transmission electron microscopy
事件响应型扫描透射电子显微镜
▲ 作者：JONATHAN J. P. PETERS, BRYAN W. REED, YU JIMBO, KANAKO NOGUCHI, KARIN H. MüLLER, ALEXANDRA PORTER, ET AL.
▲链接：
https://www.science.org/doi/10.1126/science.ado8579
▲摘要：
透射电子显微镜一个长期存在的限制是高能电子与任何样品相互作用所造成的损伤。
通过重新考虑成像的基本原理，研究组展示了一种电子显微镜的事件响应策略，可为给定光束流提供有关样品的更多信息。通过测量达到电子计数阈值的时间，而非等待预定义的常数时间，可提高每个电子获得的信息。
显微镜通过遮蔽光束来响应这些事件，从而减少所需的总剂量。该方法自动分配剂量，以在每个像素中实现给定的信噪比，消除了与信息收益递减相关的过量剂量。通过成像生物组织和沸石，研究组证明了该策略对光束敏感材料的广泛适用性。
▲ Abstract：
An ever-present limitation of transmission electron microscopy is the damage caused by high-energy electrons interacting with any sample. By reconsidering the fundamentals of imaging, we demonstrate an event-responsive approach to electron microscopy that delivers more information about the sample for a given beam current. Measuring the time to achieve an electron count threshold rather than waiting a predefined constant time improves the information obtained per electron. The microscope was made to respond to these events by blanking the beam, thus reducing the overall dose required. This approach automatically apportions dose to achieve a given signal-to-noise ratio in each pixel, eliminating excess dose that is associated with diminishing returns of information. We demonstrate the wide applicability of our approach to beam-sensitive materials by imaging biological tissue and zeolite.
Nuclei engineering for even halide distribution in stable perovskite/silicon tandem solar cells
晶核工程助力稳定钙钛矿/硅串联太阳能电池中卤化物均匀分布
▲ 作者：YIHUA CHEN, NING YANG, GUANHAOJIE ZHENG, FENGTAO PEI, WENTAO ZHOU, YU ZHANG, ET AL.
▲链接：
https://www.science.org/doi/10.1126/science.ado9104
▲摘要：
串联结构的宽带隙（WBG）吸收剂结晶度差、织构弱，在实际运行中导致了严重的混合卤化物—阳离子迁移和相分离。
研究组通过在任何富溴聚集体和2H相形成之前使3C相成核，来控制对成分不敏感的WBG膜生长。所得WBG吸收剂具有改善的结晶度和较强的织构，抑制了非辐射复合，增强了对各种老化应力的抵抗力。
钙钛矿/硅串联太阳能电池的功率转换效率在25 cm2有效面积内为29.4%（第三方评估为28.8%），在1 cm2有效面积内为32.5%。这些太阳能电池在封装后，在25℃最大功率点（AM 1.5G照明，全光谱，1太阳）下运行1301小时后，保持了98.3%的初始效率；而在50℃最大功率点下运行800小时后，亦保持了90%的初始效率。
▲ Abstract：
Wide-bandgap (WBG) absorbers in tandem configurations suffer from poor crystallinity and weak texture, which leads to severe mixed halide-cation ion migration and phase segregation during practical operation. We control WBG film growth insensitive to compositions by nucleating the 3C phase before any formation of bromine-rich aggregates and 2H phases. The resultant WBG absorbers show improved crystallinity and strong texture with suppressed nonradiative recombination and enhanced resistance to various aging stresses. Perovskite/silicon tandem solar cells achieve power conversion efficiencies of 29.4% (28.8% assessed by a third party) in a 25–square centimeter active area and 32.5% in a 1–square centimeter active area. These solar cells retained 98.3 and 90% of the original efficiency after 1301 and 800 hours of operation at 25° and 50°C, respectively, at the maximum power point (AM 1.5G illumination, full spectrum, 1-sun) when encapsulated.
Additive manufacturing of highly entangled polymer networks
高度缠结聚合物网络的增材制造
▲ 作者：ABHISHEK P. DHAND, MATTHEW D. DAVIDSON, HANNAH M. ZLOTNICK, THOMAS J. KOLIBABA, JASON P. KILLGORE AND JASON A. BURDICK
▲链接：
https://www.science.org/doi/10.1126/science.adn6925
▲摘要：
在单个网络中掺入聚合物链缠结可协同提高刚度和韧性，但通过诸如数字光处理（DLP）的光聚合固化增材制造来实现如此密集的缠结仍难以实现。
研究组报道了一种结合了光聚合和暗聚合的简单策略，使组成聚合物链在印刷结构中形成时能够紧密缠绕。
