Compiled by Weiwei Feng
Science, Volume 383, Issue 6688
Reinforcing Self-Assembly of Hole Transport Molecules for Stable Inverted Perovskite Solar Cells
Abstract: In their study, Tang et al. utilized atomic-layer deposition to stabilize self-assembled monolayers (SAMs) employed as the hole-transporting layer in perovskite solar cells (PSCs). They observed that SAMs exhibited stronger anchoring to the transparent indium tin oxide electrode after additional deposition of indium oxide through atomic-layer deposition. These films featured a high coverage of strongly chemisorbed hydroxyl groups, binding the SAM via trimethoxysilane groups. Inverted PSCs maintained 98% of their power conversion efficiency after operating at maximum power point tracking at 85°C for 1200 hours.
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Electron Injection and Defect Passivation for High-Efficiency Mesoporous Perovskite Solar Cells
Abstract: Efficiency enhancements in mesoporous perovskite solar cells have been achieved through improved electron injection via defect passivation at the titanium oxide interface. These devices feature a layered mesoporous scaffold composed of carbon, titanium dioxide, and zirconium dioxide filled with perovskite, exhibiting band alignment conducive to charge separation even without a hole-transporter layer. Liu et al. employed ammonium phosphate to passivate defects on titanium dioxide, thereby enhancing electron injection. This led to a reduction in charge recombination and a consequent increase in power conversion efficiency to approximately 22%. Devices maintained 97% of their initial efficiency after 750 hours of maximum power point tracking at 55°C.
Link: Read more A Commercially Feasible Approach to Controlling Long-Chain Branching in Polyethylene
Authors: ROBERT D. FROESE, DANIEL J. ARRIOLA, JAAP DEN DOELDER, JIANBO HOU, TERESITA KASHYAP, KERAN LU, LUCA MARTINETTI, AND BRYAN D. STUBBERT
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Abstract: Low-density polyethylene (LDPE) finds wide application in plastic films and other flexible products, owing to its properties derived from a branched molecular structure rather than a linear one. This necessitates an energy-intensive, high-pressure synthesis technique. Researchers report a novel method to achieve long-chain branching under mild solution-phase conditions. Their catalyst can simultaneously link two chains by using a small quantity of diene mixed with ethylene, forming a ladder-like geometry. The resulting plastic exhibits properties comparable to LDPE.
Two-Dimensional Materials through Large-Scale Computational Approaches and Chemical Exfoliation of Layered Solids
Authors: JONAS BJ?RK, JIE ZHOU, PER O. ?. PERSSON, AND JOHANNA ROSEN
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Abstract: MXenes represent a class of layered inorganic compounds composed of transition metal carbides, nitrides, or carbonitrides. They are typically obtained through the selective etching of three-dimensional (3D) parent materials under acidic conditions. An outstanding question is whether other layered materials could be obtained utilizing existing chemical processes. Researchers describe a method employing computational high-throughput screening to determine which 3D materials might undergo successful chemical exfoliation. They identified 119 potential candidates, from which they experimentally synthesized Ru2SixOy nanosheets from a parent YRu2Si2 compound, a material distinct from the standard families of MXenes. Grid-plainification facilitates better cooling performance in medium-temperature PbSe thermoelectrics compared to Bi2Te3
📝 Authors: Yongxin Qin, Bingchao Qin, Tao Hong, Xiao Zhang, Dongyang Wang, Dongrui Liu, Zi-Yuan Wang, Lizhong Su, Sining Wang, and Li-Dong Zhao
🔗 Link: https://www.science.org/doi/10.1126/science.adk9589
📄 Abstract: Thermoelectric cooling presents an appealing solid-state approach, albeit reliant on telluride-based materials, which are resource-constrained. Researchers have uncovered a relatively straightforward lead selenide–based material exhibiting promising cooling capabilities. By introducing additional lead into the mixture, they enhance thermoelectric efficiency by filling vacancies. Pairing this material with tin selenide, they devise a cooling apparatus showcasing attractive performance and revealing the potential for tellurium-free cooling.
🌱 Ecology
Diversity fosters stability: Sublinear growth and competitive coexistence across ecosystems
📝 Authors: Ian A. Hatton, Onofrio Mazzarisi, Ada Altieri, and Matteo Smerlak
🔗 Link: https://www.science.org/doi/10.1126/science.adg8488
📄 Abstract: Despite Earth's most biodiverse ecosystems demonstrating long-term stability, ecological theory predicts diminished stability with increased species coexistence. Conventional species coexistence models, rooted in the Lotka-Volterra framework, assume logistic population growth and self-regulation for stable coexistence. However, Hatton et al. reveal an alternative model featuring sublinear population growth, yielding divergent community predictions. Under this model, diversity enhances stability, aligning with established population time series and macroecological scaling relationships.
