bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Tandem Organic Photovoltaic Cell with 19.6% Efficiency Enabled by Light Distribution Control
Authors: Wang Jianqiu , Zheng Zhong , Zu Yunfei , Wang Yafei , Liu Xiaoyu , Zhang Shaoqing , Zhang Maojie , Hou Jianhui 
Published: August 2021

AbstractDespite more potential in realizing higher photovoltaic performance, the highest power conversion efficiency (PCE) of tandem organic photovoltaic (OPV) cells still lags behind that of state‐of‐the‐art single‐junction cells. In this work, highly efficient double‐junction tandem OPV cells are fabricated by optimizing the photoactive layers with low voltage losses and developing an effective method to tune optical field distribution. The tandem OPV cells studied are structured as indium tin oxide (ITO)/ZnO/bottom photoactive layer/interconnecting layer (ICL)/top photoactive layer/MoOx/Ag, where the bottom and top photoactive layers are based on blends of PBDB‐TF:ITCC and PBDB‐TF:BTP‐eC11, respectively, and ICL refers to interconnecting layer structured as MoOx/Ag/ZnO:PFN‐Br. As these results indicate that there is not much room for optimizing the bottom photoactive layer, more effort is put into fine‐tuning the top photoactive layer. By rationally modulating the composition and thickness of PBDB‐TF:BTP‐eC11 blend films, the 300 nm‐thick PBDB‐TF:BTP‐eC11 film with 1:2 D/A ratio is found to be an ideal photoactive layer for the top sub‐cell in terms of photovoltaic characteristics and light distribution control. For the optimized tandem cell, a PCE of 19.64% is realized, which is the highest result in the OPV field and certified as 19.50% by the National Institute of Metrology.
Synergistic Effects of Eu‐MOF on Perovskite Solar Cells with Improved Stability
Authors: Dou Jie , Zhu Cheng , Wang Hao , Han Ying , Ma Sai , Niu Xiuxiu , Li Nengxu , Shi Congbo , Qiu Zhiwen , Zhou Huanping , Bai Yang , Chen Qi 
Published: August 2021

AbstractEnhancing device lifetime is one of the essential challenges in perovskite solar cells. The ultrathin Eu‐MOF layer is introduced at the interface between the electron‐transport layer and the perovskite absorber to improve the device stability. Both Eu ions and organic ligands in the MOF can reduce the defect concentration and improve carrier transport. Moreover, due to the Förster resonance energy transfer effect, Eu‐MOF in perovskite films can improve light utilization and reduce the decomposition under ultraviolet light. Meanwhile, Eu‐MOF also turns tensile strain to compressive strain in the perovskite films. As a result, the corresponding devices achieve a champion power conversion efficiency (PCE) of 22.16%. In addition, the devices retain 96% of their original PCE after 2000 h under the relative humidity of 30% and 91% of their original PCE after 1200 h after continuous 85 °C aging condition in N2.
Magnetization Signature of Topological Surface States in a Non‐Symmorphic Superconductor
Authors: Kuang Wenjun , Lopez‐Polin Guillermo , Lee Hyungjun , Guinea Francisco , Whitehead George , Timokhin Ivan , Berdyugin Alexey I. , Kumar Roshan Krishna , Yazyev Oleg V. , Walet Niels , Principi Alessandro , Geim Andre K. , Grigorieva Irina V. 
Published: August 2021

AbstractSuperconductors with nontrivial band structure topology represent a class of materials with unconventional and potentially useful properties. Recent years have seen much success in creating artificial hybrid structures exhibiting the main characteristics of 2D topological superconductors. Yet, bulk materials known to combine inherent superconductivity with nontrivial topology remain scarce, largely because distinguishing their central characteristic—the topological surface states—has proved challenging due to a dominant contribution from the superconducting bulk. In this work, a highly anomalous behavior of surface superconductivity in topologically nontrivial 3D superconductor In2Bi, where the surface states result from its nontrivial band structure, itself a consequence of the non‐symmorphic crystal symmetry and strong spin–orbit coupling, is reported. In contrast to smoothly decreasing diamagnetic susceptibility above the bulk critical field, Hc2, as seen in conventional superconductors, a near‐perfect, Meissner‐like screening of low‐frequency magnetic fields well above Hc2 is observed. The enhanced diamagnetism disappears at a new phase transition close to the critical field of surface superconductivity, Hc3. Using theoretical modeling, the anomalous screening is shown to be consistent with modification of surface superconductivity by the topological surface states. The possibility of detecting signatures of the surface states using macroscopic magnetization provides a new tool for the discovery and identification of topological superconductors.
Hydrogen Passivation of M–N–C (M = Fe, Co) Catalysts for Storage Stability and ORR Activity Improvements
Authors: Liu Jieyuan , Wan Xin , Liu Shiyuan , Liu Xiaofang , Zheng Lirong , Yu Ronghai , Shui Jianglan 
Published: August 2021

AbstractM–N–C (M = Fe, Co) are highly active nonprecious metal electrocatalysts for the oxygen reduction reaction (ORR) and other applications. Although their operation stability has been extensively studied in proton‐exchange‐membrane fuel cells, the storage stability that determines the performance maintenance before use has not yet been understood. Here, it is found that long‐term exposure of M–N–C catalysts in air would cause surface oxidation and hydroxylation, resulting in significant decrease of ORR activity and fuel‐cell performances. Hydrogen passivation is demonstrated to be an effective strategy to protect the atomic M–N4 active sites and improve the storage stability of the catalysts. In addition, the hydrogen‐termination can also reduce the ORR energy barrier and increase the utilization of active sites, leading to the improvements of fuel‐cell activity and power density. Notably, these findings help to understand the storage‐associated degradation and protection of M–N–C catalysts.
Molecular Engineering of Covalent Organic Framework Cathodes for Enhanced Zinc‐Ion Batteries
Authors: Wang Wenxi , Kale Vinayak S. , Cao Zhen , Lei Yougjiu , Kandambeth Sharath , Zou Guodong , Zhu Yunpei , Abouhamad Edy , Shekhah Osama , Cavallo Luigi , Eddaoudi Mohamed , Alshareef Husam N. 
Published: August 2021

AbstractCovalent organic frameworks (COFs) are potentially promising electrode materials for electrochemical charge storage applications thanks to their pre‐designable reticular chemistry with atomic precision, allowing precise control of pore size, redox‐active functional moieties, and stable covalent frameworks. However, studies on the mechanistic and practical aspects of their zinc‐ion storage behavior are still limited. In this study, a strategy to enhance the electrochemical performance of COF cathodes in zinc‐ion batteries (ZIBs) by introducing the quinone group into 1,4,5,8,9,12‐hexaazatriphenylene‐based COFs is reported. Electrochemical characterization demonstrates that the introduction of the quinone groups in the COF significantly pushes up the Zn2+ storage capability against H+ and elevates the average (dis‐)charge potential in aqueous ZIBs. Computational and experimental analysis further reveals the favorable redox‐active sites that host Zn2+/H+ in COF electrodes and the root cause for the enhanced electrochemical performance. This work demonstrates that molecular engineering of the COF structure is an effective approach to achieve practical charge storage performance.
Spontaneous Production of Ultrastable Reactive Oxygen Species on Titanium Oxide Surfaces Modified with Organic Ligands
Authors: Ritacco Ida , Imparato Claudio , Falivene Laura , Cavallo Luigi , Magistrato Alessandra , Caporaso Lucia , Farnesi Camellone Matteo , Aronne Antonio 
Published: August 2021

AbstractThe spontaneous formation and long‐term surface stabilization of superoxide radicals are observed on specific TiO2 hybrid materials in which titanium is coordinated to an organic ligand. Here the rationale for this uncommon phenomenon is investigated by a synergistic theoretical and experimental approach involving density functional theory (DFT) calculations and spectroscopic techniques. Stoichiometric and reduced anatase (101) surfaces modified with acetylacetone, dibenzoylmethane, and catechol are comparatively examined. These results reveal that the interaction between organic ligands and adsorbed O2 molecules improves when O vacancies are present on the external layer of the surface, promoting O2 reduction. The electronic features of the ligand play a pivotal role for both an effective electronic interaction with the surface and the stabilization of the generated reactive oxygen species. These results agree with experimental data showing that sol–gel‐derived Ti‐diketonate hybrid oxides spontaneously produce very persistent superoxide radicals under ambient conditions, thus holding a high intrinsic oxidative activity.
MXene Reinforced Thermosetting Composite for Lightning Strike Protection of Carbon Fiber Reinforced Polymer
Authors: Kumar Vipin , Yeole Pritesh , Majed Ahmad , Park Chanyeop , Li Kai , Naguib Michael , Ravindranath Pruthul Kokkada , Jafta Charl , Spencer Ryan , Compton Brett , Vaidya Uday , Kunc Vlastimil 
Published: August 2021

AbstractTi3C2 – a member of the MXenes (2D transition metal carbides and nitrides) family, is investigated as an effective filler to improve the electrical, mechanical, and thermal properties of divinylbenzene (DVB) thermosetting resin. Consequently, its performance as a lightning strike protection (LSP) coating for carbon fiber reinforced polymer (CFRP) is evaluated. Polyaniline (PANI) – dodecylbenzene sulfonic acid (DBSA) complex is used to cure the DVB resin. The synergic effect of MXenes (with surface that is negatively charged) with polyaniline (positive charge) shows electrostatic bonding and improved electrical conductivity in the composite. The addition of MXenes at 2 wt% into the PANI‐DVB composite shows ≈139%, 10%, and 9% improvement in electrical conductivity, flexural strength, and flexural modulus, respectively, compared to the neat PANI‐DVB composite. The composites are investigated using various material characterization techniques including Fourier transforms infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, and scanning electron microscopy. Furthermore, MXenes‐DVB is utilized to create a conductive thermosetting coating on top of a CFRP substrate and tested against a lightning strike of 100 kA. CFRP with MXenes‐DVB coating reduced the surface damage from 40.61 cm2 (reference CFRP panel) to 13.29 cm2 (CFRP coated with MXenes‐DVB).
Design of Electrochemical Microfluidic Detectors: A Review
Authors: Li Tianyu , Díaz‐Real Jesús Adrián , Holm Thomas 
Published: August 2021

AbstractMiniaturized electrochemical systems integrated into microfluidic flow devices have been an active research field the last couple of decades. This has resulted in many advanced microfluidic platforms for the conversion and detection of chemicals. The development is partly driven by the increased access to and decreased cost of fabrication. In the design of microfluidic electrochemical cells, several aspects need to be handled, such as the accurate control of potential, electrolyte flow, pH, pressure, and temperature. This can be further complicated by integrating photon traffic for spectro(electro)chemical detection. Here, a comprehensive review of recent advances and approaches to the design of microfluidic flow devices for detection is presented, first dealing with the design of electrodes and flow pathways, then highlighting some common challenges and how these have been dealt with in the literature. This work aims to be a guide for researchers in the design of microfluidic electrochemical systems for detection of chemical species.
Dexamethasone (DXM)‐Coated Poly(lactic‐co‐glycolic acid) (PLGA) Microneedles as an Improved Drug Delivery System for Intracochlear Biodegradable Devices
Authors: Pawley Devon C. , Goncalves Stefania , Bas Esperanza , Dikici Emre , Deo Sapna K. , Daunert Sylvia , Telischi Fred 
Published: August 2021

AbstractUniform drug delivery techniques are challenging to develop for the inner ear due to the complexity of the cochlear anatomy. A promising solution is the use of biodegradable polymers because the continuous release of therapeutics without introducing toxic compounds is desirable. Using a microneedle approach lends the polymeric microneedle the capability to be placed inside of the scala tympani, releasing drugs overtime. Poly(lactic‐co‐glycolic acid) (PLGA) microneedles is prepared by dissolving dimethyl sulfoxide with either a) Rhodamine B, to study the drug release profile in vitro, b) FM1‐43, to study the drug release profile in vivo, or c) dexamethasone (DXM), to protect hair cell (HC) loss in vivo. The Rhodamine B studies show that the dye begins release from the microneedles within 30 min. The ototoxicity assessment of the DXM‐coated microneedles in vitro shows a significant reduction of HC losses when compared to control microneedles in an ototoxic environment. In vivo data show reduced hearing threshold for animals treated with DXM‐infused microneedles, providing a proof of concept of the methodology developed. Drug‐infused polymeric microneedles provide a promising method to deliver DXM to the inner ear over controlled periods of time protecting hair cells, thus minimizing hearing loss (HL).
CHAF1A Blocks Neuronal Differentiation and Promotes Neuroblastoma Oncogenesis via Metabolic Reprogramming
Authors: Tao Ling , Moreno‐Smith Myrthala , Ibarra‐García‐Padilla Rodrigo , Milazzo Giorgio , Drolet Nathan A. , Hernandez Blanca E. , Oh Young S. , Patel Ivanshi , Kim Jean J. , Zorman Barry , Patel Tajhal , Kamal Abu Hena Mostafa , Zhao Yanling , Hicks John , Vasudevan Sanjeev A. , Putluri Nagireddy , Coarfa Cristian , Sumazin Pavel , Perini Giovanni , Parchem Ronald J. , Uribe Rosa A. , Barbieri Eveline 
Published: August 2021

AbstractNeuroblastoma (NB) arises from oncogenic disruption of neural crest (NC) differentiation. Treatment with retinoic acid (RA) to induce differentiation has improved survival in some NB patients, but not all patients respond, and most NBs eventually develop resistance to RA. Loss of the chromatin modifier chromatin assembly factor 1 subunit p150 (CHAF1A) promotes NB cell differentiation; however, the mechanism by which CHAF1A drives NB oncogenesis has remained unexplored. This study shows that CHAF1A gain‐of‐function supports cell malignancy, blocks neuronal differentiation in three models (zebrafish NC, human NC, and human NB), and promotes NB oncogenesis. Mechanistically, CHAF1A upregulates polyamine metabolism, which blocks neuronal differentiation and promotes cell cycle progression. Targeting polyamine synthesis promotes NB differentiation and enhances the anti‐tumor activity of RA. The authors' results provide insight into the mechanisms that drive NB oncogenesis and suggest a rapidly translatable therapeutic approach (DFMO plus RA) to enhance the clinical efficacy of differentiation therapy in NB patients.
IRF8 Impacts Self‐Renewal of Hematopoietic Stem Cells by Regulating TLR9 Signaling Pathway of Innate Immune Cells
Authors: Li Donghe , Zhang Yuyin , Qiu Qingsong , Wang Jinzeng , Zhao Xuemei , Jiao Bo , Zhang Xiuli , Yu Shanhe , Xu Pengfei , Dan Yuqing , Xiao Xinhua , Wang Peihong , Liu Mingzhu , Xia Zhizhou , Huang Zhangsen , Zhang Ruihong , Li Jiaoyang , Xie Xi , Zhang Yan , Liu Chenxuan , Liu Ping , Ren Ruibao 
Published: August 2021

AbstractIRF8 is a key regulator of innate immunity receptor signaling and plays diverse functions in the development of hematopoietic cells. The effects of IRF8 on hematopoietic stem cells (HSCs) are still unknown. Here, it is demonstrated that IRF8 deficiency results in a decreased number of long‐term HSCs (LT‐HSCs) in mice. However, the repopulation capacity of individual HSCs is significantly increased. Transcriptomic analysis shows that IFN‐γ and IFN‐α signaling is downregulated in IRF8‐deficient HSCs, while their response to proinflammatory cytokines is unchanged ex vivo. Further tests show that Irf8−/− HSCs can not respond to CpG, an agonist of Toll‐like receptor 9 (TLR9) in mice, while long‐term CpG stimulation increases wild‐type HSC abundance and decreases their bone marrow colony‐forming capacity. Mechanistically, as the primary producer of proinflammatory cytokines in response to CpG stimulation, dendritic cells has a blocked TLR9 signaling due to developmental defect in Irf8−/− mice. Macrophages remain functionally intact but severely reduce in Irf8−/− mice. In NK cells, IRF8 directly regulates the expression of Tlr9 and its deficiency leads to no increased IFNγ production upon CpG stimulation. These results indicate that IRF8 regulates HSCs, at least in part, through controlling TLR9 signaling in diverse innate immune cells.
Ultrasensitive Photodetection in MoS2 Avalanche Phototransistors
Authors: Seo Junseok , Lee Jin Hee , Pak Jinsu , Cho Kyungjune , Kim Jae‐Keun , Kim Jaeyoung , Jang Juntae , Ahn Heebeom , Lim Seong Chu , Chung Seungjun , Kang Keehoon , Lee Takhee 
Published: August 2021

AbstractRecently, there have been numerous studies on utilizing surface treatments or photosensitizing layers to improve photodetectors based on 2D materials. Meanwhile, avalanche breakdown phenomenon has provided an ultimate high‐gain route toward photodetection in the form of single‐photon detectors. Here, the authors report ultrasensitive avalanche phototransistors based on monolayer MoS2 synthesized by chemical vapor deposition. A lower critical field for the electrical breakdown under illumination shows strong evidence for avalanche breakdown initiated by photogenerated carriers in MoS2 channel. By utilizing the photo‐initiated carrier multiplication, their avalanche photodetectors exhibit the maximum responsivity of ≈3.4 × 107 A W−1 and the detectivity of ≈4.3 × 1016 Jones under a low dark current, which are a few orders of magnitudes higher than the highest values reported previously, despite the absence of any additional chemical treatments or photosensitizing layers. The realization of both the ultrahigh photoresponsivity and detectivity is attributed to the interplay between the carrier multiplication by avalanche breakdown and carrier injection across a Schottky barrier between the channel and metal electrodes. This work presents a simple and powerful method to enhance the performance of photodetectors based on carrier multiplication phenomena in 2D materials and provides the underlying physics of atomically thin avalanche photodetectors.
Interfacial Control via Reversible Ionic Motion in Battery‐Like Magnetic Tunnel Junctions
Authors: Long Guofei , Xue Qian , Li Qiang , Shi Yu , Li Lin , Cheng Long , Li Peng , Zhang Junwei , Zhang Xixiang , Guo Haizhong , Fu Jing , Li Shandong , Moodera Jagadeesh S. , Miao Guo‐Xing 
Published: August 2021

AbstractElectrical control on interfaces is one of the key approaches to harvest advanced functionalities in modern electronic devices. In this work, it is proposed and demonstrated that a “battery‐like” tunnel junction structure can be embedded with added control and functionalities via reversible lithium‐ion motion. In a model system of FeCo/FeCoOx/LiF/FeCo magnetic tunnel junctions, the ultrathin LiF barrier makes strong electric fields possible under moderate applied voltages, and can therefore electrically drive reversible lithium‐ion migration within the barrier. The ion motion subsequently leads to reversible interfacial modifications that generates over a thousand percent resistance change across the devices. Meanwhile, sizable tunneling magnetoresistance persists and even reverses the sign of spin polarization as a function of the interfacial control. The devices are therefore responsive to both electric and magnetic field manipulations, giving rise to diverse and nonvolatile functionalities.
Revealing the Real Role of Nickel Decorated Nitrogen‐Doped Carbon Catalysts for Electrochemical Reduction of CO2 to CO
Authors: Liang Shuyu , Jiang Qian , Wang Qiang , Liu Yuefeng 
Published: August 2021

AbstractIt is widely accepted that single Ni atoms coordinated with N can highly efficiently promote CO2 electroreduction to CO. Very recently, probably due to limited access to high‐angle annular dark‐field scanning transmission electron microscopy (HAADF‐STEM) techniques, a misleading conclusion that nitrogen‐doped carbon‐encapsulated Ni nanoparticles (NPs) possess activity similar to that of single Ni atoms was reported and was quickly followed by several similar reports. The current contribution aims to end this misleading conclusion by performing well‐designed experiments and solid theoretical analyses. For this purpose, a series of Ni/nitrogen‐doped graphite (Ni‐NG) catalysts with different dominant Ni species (single Ni atom, nitrogen‐doped carbon‐encapsulated Ni NPs, or both) are fabricated and comparatively studied for CO2 electroreduction to CO. Two previous studies that reported nitrogen‐doped carbon‐encapsulated Ni NPs catalysts are reinvestigated, and the existence of single Ni atoms is confirmed by HAADF‐STEM. In addition, after leaching out most of the Ni NPs by a strong acid, the activity of those catalysts does not decrease but increases slightly. Density functional theory results suggest that nitrogen‐doped carbon‐encapsulated Ni NPs are highly selective for the hydrogen evolution reaction (HER) rather than for CO2‐to‐CO conversion. Overall, both systematic experimental and theoretical analyses clearly reveal that the nitrogen‐doped carbon‐encapsulated Ni NPs are not active for CO2 electroreduction.
Deciphering Interfacial Reactions via Optical Sensing to Tune the Interphase Chemistry for Optimized Na‐Ion Electrolyte Formulation
Authors: Desai Parth , Huang Jiaqiang , Hijazi Hussein , Zhang Leiting , Mariyappan Sathiya , Tarascon Jean‐Marie 
Published: August 2021

AbstractInterphases, solid‐electrolyte interphase (SEI), and cathode‐electrolyte interphase (CEI) are the key influencers in determining battery life and performance. Especially, for technologies such as sodium‐ion batteries that are in the development stage, it is crucial to tune the interphase chemistry without which it suffers at present from poor performance metrics for reaching real‐life applications. In this study, optical sensors are utilized as a tool to follow operando, the thermal events of interfacial reactions, and establish the role of different electrolyte additives during the SEI/CEI formation. Using the acquired knowledge from sensing, together with complementary studies in Na‐ion full‐cells, a new electrolyte formulation is proposed that shows stable cycling performance at 0–55 °C with very low self‐discharge and improves safety due to mitigated gassing during cycling. Finally, the studies are nurtured by transferring the know‐how to prototype cylindrical 18 650 cells. It is hoped that such findings will accelerate the practical development of Na‐ion batteries.