bluuebunny/crossref_metadata_2025_split huggingface dataset:
Highly Stable Contact Doping in Organic Field Effect Transistors by Dopant‐Blockade Method
Authors: Kim Youngrok , Broch Katharina , Lee Woocheol , Ahn Heebeom , Lee Jonghoon , Yoo Daekyoung , Kim Junwoo , Chung Seungjun , Sirringhaus Henning , Kang Keehoon , Lee Takhee 
Published: May 2020

AbstractIn organic device applications, a high contact resistance between metal electrodes and organic semiconductors prevents an efficient charge injection and extraction, which fundamentally limits the device performance. Recently, various contact doping methods have been reported as an effective way to resolve the contact resistance problem. However, the contact doping has not been explored extensively in organic field effect transistors (OFETs) due to dopant diffusion problem, which significantly degrades the device stability by damaging the ON/OFF switching performance. Here, the stability of a contact doping method is improved by incorporating “dopant‐blockade molecules” in the poly(2,5‐bis(3‐hexadecylthiophen‐2‐yl)thieno[3,2‐b]thiophene) (PBTTT) film in order to suppress the diffusion of the dopant molecules. By carefully selecting the dopant‐blockade molecules for effectively blocking the dopant diffusion paths, the ON/OFF ratio of PBTTT OFETs can be maintained over 2 months. This work will maximize the potential of OFETs by employing the contact doping method as a promising route toward resolving the contact resistance problem.
Towards Simplifying the Device Structure of High‐Performance Perovskite Solar Cells
Authors: Huang Yulan , Liu Tanghao , Liang Chao , Xia Junmin , Li Dongyang , Zhang Haichao , Amini Abbas , Xing Guichuan , Cheng Chun 
Published: May 2020

AbstractPerovskite solar cells (PSCs) are considered one of the most promising next‐generation examples of high‐tech photovoltaic energy converters, as they possess an unprecedented power conversion efficiency with low cost. A typical high‐performance PSC generally contains a perovskite active layer sandwiched between an electron‐transport layer (ETL) and a hole‐transport layer (HTL). The ETL and HTL contribute to the charge extraction in the PSC. However, these additional two layers complicate the manufacturing process and raise the cost. To extend this technology for commercialization, it is highly desired that the structure of PSCs is further simplified without sacrificing their photovoltaic performances. Thus, ETL‐free or/and HTL‐free PSCs are developed and attract more and more interest. Herein, the commonly used methods in reducing the defect density and optimizing the energy levels in conventional PSCs in order to simplify their structures are summarized. Then, the development of diverse ETL‐free or/and HTL‐free PSCs is discussed, with the PSCs classified, including their working principles, implemented technologies, remaining challenges, and future perspectives. The aim is to redirect the way toward low‐cost and high‐performance PSCs with the simplest possible architecture.
Oxygen‐Vacancy‐Endurable Conductors with Enhanced Transparency Using Correlated 4d2 SrMoO3 Thin Films
Authors: Ha Youngkyoung , Lee Shinbuhm 
Published: May 2020

AbstractDegenerately doped wide‐bandgap semiconductors, e.g., Sn‐doped In2O3, are the most conventional transparent conductors (TCs), but degradation of the TC performance by a doping bottleneck or instability due to oxygen vacancies is encountered. Recently, nondoped correlated metals have attracted great attention as a new strategy for developing next‐generation TCs. To date, most studies of this brand‐new type of TC have been biased toward 3d1 vanadates. Here, compared with 3d1 SrVO3, it is found that the 4d2 SrMoO3 thin films show promising TC properties: higher ultraviolet–visible transmittance of 80% and extremely low resistivity of 100 µΩ cm at room temperature. This enhancement in the SrMoO3 is ascribed to a p‐4d transition occurring at higher photon energy and a higher number of electrons in the outermost 4d orbitals, respectively. In addition, the TC properties of the correlated SrMoO3 are resistive to oxygen vacancies. Using spectroscopic ellipsometry, it is found that this robustness is attributed to the lack of formation of defect states near the Fermi level, which is different from the observation in conventional TCs. Taken together, the correlated 4d2 SrMoO3 is appealing for next‐generation oxygen‐vacancy‐endurable conductors with enhanced transparency.
High Solid‐State Near Infrared Emissive Organic Fluorophores from Thiadiazole[3,4‐c]Pyridine Derivatives for Efficient Simple Solution‐Processed Nondoped Near Infrared OLEDs
Authors: Therdkatanyuphong Pattarawadee , Chasing Pongsakorn , Kaiyasuan Chokchai , Boonnab Sumita , Sudyoadsuk Taweesak , Promarak Vinich 
Published: May 2020

AbstractMany efforts have been dedicated to developing near infrared (NIR) fluorescent emitters with strong emission especially in the range of 700–1000 nm due to their potential applications in biomedical and optoelectronic fields. However, high solid state NIR emission fluorophores are still rare for applications. Herein, two efficient donor‐π‐acceptor type NIR emitters, C3HTP and C4HTP, are designed and synthesized by end‐capping two isomeric bis(n‐hexylthienyl)thiadiazole[3,4‐c]pyridines as π‐acceptor with structural bulky, electron rich tercarbazole moiety. They exhibit excellent solid state NIR emission with an emission peak at 725 nm, especially C3HTP, reaching a record high photoluminescence quantum yield (ΦPL) of 34% for NIR organic fluorescent materials. By taking advantage of their ΦPL values in the film state (ΦPL = 10–34%), suitable energy levels (highest occupied molecular orbital (HOMO) level ≈ −5.3 eV), high hole mobility (5.49 × 10−8 cm2 V−1 s−1) as well as good amorphous film forming ability by solution casting, they are used to fabricate a nondoped emissive layer (EML) in simple double‐layer solution processed NIR electroluminescent (EL) devices. The device containing C3HTP as the EML shows a NIR emission peaking at 726 nm and excellent EL performance with a high external quantum efficiency of 1.51%, which is the best solution processed nondoped NIR organic light‐emitting diodes reported to date. Importantly, this represents an advance in near infrared organic fluorescent materials and EL devices that meet the requirements of many applications.
A New Concept and Strategy for Photovoltaic and Thermoelectric Power Generation Based on Anisotropic Crystal Facet Unit
Authors: Li Yang , Luo Kai , Tao Ran , Wang Zhiyong , Chen Daifen , Shao Zongping 
Published: May 2020

AbstractAccording to the classic concept of photovoltaic devices, p–n junctions and heterojunctions are indispensable for carrier separation. Herein, for the first time, a novel concept of “anisotropic crystal facet unit” is put forward and clarified for photovoltaic and thermoelectric power generation. Specifically, an “anisotropic crystal facet unit” in monocrystalline p‐Cu2O between the {100} and the {111} crystal faces is built, which can fulfill self‐motivated carrier separation, due to their natural energy difference. The “anisotropic crystal facet unit” devices can directly and efficiently convert light and heat into electricity, where the {100} and the {111} faces act as the cathode and the anode, respectively. Moreover, hot and cold regions are unnecessary when the “anisotropic crystal facet unit” is applied in thermoelectric conversion. These findings may update the understanding of solar cells and thermoelectric cells, and blaze a new trail through the development of efficient and low‐cost energy utilization technologies.
Engineered PD‐L1‐Expressing Platelets Reverse New‐Onset Type 1 Diabetes
Authors: Zhang Xudong , Kang Yang , Wang Jinqiang , Yan Junjie , Chen Qian , Cheng Hao , Huang Peng , Gu Zhen 
Published: May 2020

AbstractThe pathogenesis of Type 1 diabetes (T1D) arises from the destruction of insulin‐producing β‐cells by islet‐specific autoreactive T cells. Inhibition of islet‐specific autoreactive T cells to rescue β‐cells is a promising approach to treat new‐onset T1D. The immune checkpoint signal axis programmed death‐1/programmed death‐ligand 1 (PD‐1/PD‐L1) can effectively regulate the activity of T cells and prevent autoimmune attack. Here, megakaryocyte progenitor cells are genetically engineered to overexpress PD‐L1 to produce immunosuppressive platelets. The PD‐L1‐overexpressing platelets (designated PD‐L1 platelets) accumulate in the inflamed pancreas and may suppress the activity of pancreas autoreactive T cells in newly hyperglycemic non‐obese diabetic (NOD) mice, protecting the insulin‐producing β‐cells from destruction. Moreover, PD‐L1 platelet treatment also increases the percentage of the regulatory T cells (Tregs) and maintains immune tolerance in the pancreas. It is demonstrated that the rescue of β‐cells by PD‐L1 platelets can effectively maintain normoglycemia and reverse diabetes in newly hyperglycemic NOD mice.
A High‐Performance Carbonate‐Free Lithium|Garnet Interface Enabled by a Trace Amount of Sodium
Authors: Fu Xingjie , Wang Tiantian , Shen Wenzhong , Jiang Miaoli , Wang Youwei , Dai Qiushi , Wang Da , Qiu Zhenping , Zhang Yelong , Deng Kuirong , Zeng Qingguang , Zhao Ning , Guo Xiangxin , Liu Zheng , Liu Jianjun , Peng Zhangquan 
Published: May 2020

AbstractGarnet‐type solid‐state electrolytes (SSEs) are promising for the realization of next‐generation high‐energy‐density Li metal batteries. However, a critical issue associated with the garnet electrolytes is the poor physical contact between the Li anode and the garnet SSE and the resultant high interfacial resistance. Here, it is reported that the Li|garnet interface challenge can be addressed by using Li metal doped with 0.5 wt% Na (denoted as Li*) and melt‐casting the Li* onto the garnet SSE surface. A mechanistic study, using Li6.4La3Zr1.4Ta0.6O12 (LLZTO) as a model SSE, reveals that Li2CO3 resides within the grain boundaries of newly polished LLZTO pellet, which is difficult to remove and hinders the wetting process. The Li* melt can phase‐transfer the Li2CO3 from the LLZTO grain boundary to the Li*’s top surface, and therefore facilitates the wetting process. The obtained Li*|LLZTO demonstrates a low interfacial resistance, high rate capability, and long cycle life, and can find applications in future all‐solid‐state batteries (e.g., Li*|LLZTO|LiFePO4).
A Lipid‐Nanopillar‐Array‐Based Immunosorbent Assay
Authors: Kim Jieun , Kim Sungi , Ahn Junhyoung , Lee JaeJong , Nam Jwa‐Min 
Published: May 2020

AbstractSince infectious diseases, particularly viral infections, have threatened human health and caused huge economical losses globally, a rapid, sensitive, and selective virus detection platform is highly demanded. Enzyme‐linked immunosorbent assay (ELISA) with flat solid substrates has been dominantly used in detecting whole viruses for its straightforwardness and simplicity in assay protocols, but it often suffers from limited sensitivity, poor quantification range, and a time‐consuming assay procedure. Here, a lipid‐nanopillar‐array‐based immunosorbent assay (LNAIA) is developed with a nanopillar‐supported lipid bilayer substrate with fluorophore‐modified antibodies for rapid, sensitive, and quantitative detection of viruses. 3D nanopillar array structures and fluid antibodies with fluorophores facilitate faster and efficient target binding and rapid fluorophore localization for quick, reliable analysis on binding events with a conventional fluorescence microscopy setup. LNAIA enables quantification of H1N1 virus that targets down to 150 virus particles with 5‐orders‐of‐magnitude dynamic range within 25 min, which cannot be achieved with conventional ELISA platforms.
Water‐Resistant Conformal Hybrid Electrodes for Aquatic Endurable Electrocardiographic Monitoring
Authors: Ji Shaobo , Wan Changjin , Wang Ting , Li Qingsong , Chen Geng , Wang Jianwu , Liu Zhiyuan , Yang Hui , Liu Xijian , Chen Xiaodong 
Published: May 2020

AbstractUnderwater vital signs monitoring of respiratory rate, blood pressure, and the heart's status is essential for healthcare and sports management. Real‐time electrocardiography (ECG) monitoring underwater can be one solution for this. However, the current electrodes used for ECGs are not suitable for aquatic applications since they may lose their adhesiveness to skin, stable conductivity, or/and structural stability when immersed into water. Here, the design and fabrication of water‐resistant electrodes to repurpose stretchable electrodes for applications in an aquatic environment are reported. The electrodes are composed of stretchable metal–polymer composite film as the substrate and dopamine‐containing polymer as a coating. The polymer is designed to possess underwater adhesiveness from the dopamine motif, water stability from the main scaffold, and ionic conductivity from the carboxyl groups for signal transmission. Stable underwater conductivity and firm adhesion to skin allow the electrodes to collect reliable ECG signals under various conditions in water. It is shown that wearable devices incorporated with the water‐resistant electrodes can acquire real‐time ECG signals during swimming, which can be used for revealing the heart condition. These water‐resistant electrodes realize underwater detection of ECG signals and can be used for health monitoring and sports management during aquatic activities.
Entrapping Living Probiotics into Collagen Scaffolds: A New Class of Biomaterials for Antibiotic‐Free Therapy of Bacterial Vaginosis
Authors: González Ana , Sabio Laura , Hurtado Carmen , Ramírez‐Rodríguez Gloria B. , Bansal Vipul , Delgado‐López José M. , Dominguez‐Vera José M. 
Published: May 2020

AbstractA new concept of biomaterials for antibiotic‐free therapy of bacterial vaginosis (BV) is here proposed. These biomaterials are obtained by entrapping two probiotic biofilms, viz., Lactobacillus fermentum (Lf) and Lactobacillus acidophilus (La) into scaffolds of self‐assembled collagen fibers (col). An in‐depth characterization and viability assays are performed on the resulting biomaterials. Results demonstrated that the collagen matrix plays a multifold role in improving the probiotic efficacy in a BV‐simulated environment: i) it acts as a host to the formation of the probiotic biofilm, ii) it protects live probiotics during storage under harsh conditions, iii) it enhances the metabolic activity of entrapped probiotics thereby restoring the pH of BV‐simulated microenvironment, and iv) it enhances the adhesion of probiotics to the simulated vaginal mucosa. These collective properties make these biomaterials as promising candidates for treating BV without antibiotics. In addition, the approach here presented can be adapted for the treatment of other complex microbial infections.
Photothermally Reconfigurable Shape Memory Magnetic Cilia
Authors: Liu Jessica A.‐C. , Evans Benjamin A. , Tracy Joseph B. 
Published: May 2020

AbstractStimulus‐responsive polymers are attractive for microactuators because they can be easily miniaturized and remotely actuated, enabling untethered operation. In this work, magnetic Fe microparticles are dispersed in a thermoplastic polyurethane shape memory polymer matrix and formed into artificial, magnetic cilia by solvent casting within the vertical magnetic field in the gap between two permanent magnets. Interactions of the magnetic moments of the microparticles, aligned by the applied magnetic field, drive self‐assembly of magnetic cilia along the field direction. The resulting magnetic cilia are reconfigurable using light and magnetic fields as remote stimuli. Temporary shapes obtained through combined magnetic actuation and photothermal heating can be locked by switching off the light and magnetic field. Subsequently turning on the light without the magnetic field drives recovery of the permanent shape. The permanent shape can also be reprogrammed after preparing the cilia by applying mechanical constraints and annealing at high temperature. Spatially controlled actuation is demonstrated by applying a mask for optical pattern transfer into the array of magnetic cilia. A theoretical model is developed for predicting the response of shape memory magnetic cilia and elucidates physical mechanisms behind observed phenomena, enabling the design and optimization of ciliary systems for specific applications.
Terahertz Sensing with Optimized Q/Veff Metasurface Cavities
Authors: Gupta Manoj , Singh Ranjan 
Published: May 2020

AbstractConfinement of electromagnetic radiation in a subwavelength cavity is an important platform for strong light–matter interaction as it enables efficient design of photonic switches, modulators, and ultrasensitive sensors. Metallic metasurfaces consist of an array of planar cavities that allow easy access to confined electromagnetic modes on the surface. However, the radiative and nonradiative losses limit the quality factor (Q) of the resonantly confined mode. Therefore, metasurface designs with effectively low mode volume (Veff) cavities become extremely important for enhancing the photonic density of states. Here, a symmetric Lorentzian resonant metasurface with lower Veff is demonstrated as compared to asymmetric Fano resonators. Lower mode volume and optimized Q/Veff metasurfaces reveal enhanced sensitivity for ultrathin analyte overlayers deposited on metasurfaces signaling enhanced light–matter interaction. Such metasurfaces with tightly confined electromagnetic modes could find wide range of applications in the development of terahertz metadevices including ultrasensitive sensors, bandpass filters, and energy‐efficient modulators.
Flexible and Rewritable Non‐Volatile Photomemory Based on Inorganic Lanthanide‐Doped Photochromic Thin Films
Authors: Chen Haisheng , Dong Zhengang , Chen Wenwen , Sun Lu , Du Xiaona , Zhao Yanan , Chen Ping , Wu Zhenping , Liu Weiwei , Zhang Yang 
Published: May 2020

AbstractEmerging wearable electronics are spurring unprecedented enthusiasm in the pursuit of next‐generation memory realizable on flexible substrates. Photochromic materials enable reversible manipulation and possess erasable/rewritable capability, which ensure them to be adequate candidates as optical memories. Nevertheless, it has been challenging to develop a flexible optical memory with organic photochromic elements that simultaneously meets the stringent thermo‐ and photostable requirements. Inorganic lanthanide Er3+‐doped bismuth layer‐structure ferroelectric Na0.5Bi2.5Nb2O9 (NBN:Er) exhibits superior photochromic performance. The coupling between lanthanide upconversion emission and photochromic effect enables rewritable and nondestructive readout characteristics. Low‐dimensional complex oxide materials have superior mechanical properties and can be subject to large strain by integration with flexible substrates. Recent advances in synthesizing high‐quality inorganic oxide films on flexible substrates provide new opportunities to build flexible optical memories with dramatically higher performance. Herein, NBN:Er thin films have been integrated with flexible polyimide substrates. These hybrid heterostructures demonstrate comprehensive robust characteristics that sustain well during the 105 bending cycles, and maintain stability over many write–read–erase cycles. This work addresses the main problems hampering the promising applications of inorganic photochromic materials and paves the way for developing more flexible and compact optical memories.
High‐Performance Broadband Photodetectors of Heterogeneous 2D Inorganic Molecular Sb2O3/Monolayer MoS2 Crystals Grown via Chemical Vapor Deposition
Authors: Ye Kun , Liu Lixuan , Huang Junquan , Nie Anmin , Zhai Kun , Wang Bochong , Wen Fusheng , Mu Congpu , Zhao Zhisheng , Gong Yongji , Xiang Jianyong , Tian Yongjun , Liu Zhongyuan 
Published: May 2020

AbstractThe newly emerged 2D materials heterostructures, including layered and nonlayered structures, are regarded as the building blocks for future high performance optoelectronic devices. However, it still remains a great challenge to directly synthesize 2D heterostructures for realizing broadband detection in photodetectors. In this work, the growth of vertically stacked inorganic molecular Sb2O3/monolayer MoS2 heterostructures through a two‐step chemical vapor deposition method is demonstrated, and high performance ultraviolet/near‐infrared photodetectors based on the achieved heterostructures are further developed. Excellent responsivity of 5.3 × 104 A W−1 and detectivity of 2.0 × 1015 Jones are obtained under 457 nm illumination. Additionally, the photodetection range can be extended to near‐infrared region. Maximum responsivity of 7.8 A W−1, detectivity of 3.4 × 1011 Jones, and fast response speed (<60 ms) are obtained under 1064 nm laser illumination at room temperature, which is far superior to those of the previously reported ultra‐thin 2D van de Waals heterostructures. The inorganic molecular Sb2O3/monolayer MoS2 heterostructures enrich the family of 2D materials heterostructures, showing potential applications in high performance functional electronics and optoelectronics.
Self‐Quenching‐Resistant Red Emissive Carbon Dots with High Stability for Warm White Light‐Emitting Diodes with a High Color Rendering Index
Authors: Zhang Xiaoqin , Yang Haiyao , Wan Zhijun , Su Ting , Zhang Xuejie , Zhuang Jianle , Lei Bingfu , Liu Yingliang , Hu Chaofan 
Published: May 2020

AbstractDue to the excellent characteristics of energy‐saving, environmentally friendly and long‐life, the solid‐state lighting based on white light‐emitting diodes (WLEDs) is an emerging technology to replace traditional lighting solutions. However, the lack of red component of the most established method for fabricating commercial WLEDs results in high correlated color temperature (CCT) and low color rendering index (CRI). Herein, red‐emitting carbon dots (R‐CDs) with self‐quenching‐resistant property are synthesized using melamine and dithiosalicylic acid as precursors. In addition, R‐CDs exhibit high thermal and photostability under high temperature and strong blue light irradiation. On the basis of the unique features of R‐CDs, a WLED is fabricated by combining a blue‐LED chip with commercial Ce3+:Y3Al5O12 and R‐CDs phosphors, which exhibits warm white light with a color coordinate of (0.41, 0.38), a high CRI of 92.7 and a CCT of 3827 K. Besides, the WLED exhibits good optical stability upon the increase of drive current from 20 to 100 mA. The results suggest R‐CDs can be used as a color converter to fabricate high‐quality warm WLEDs.
Independent Energy Allocation of Dual‐Helical Multi‐Beams with Spin‐Selective Transmissive Metasurface
Authors: Ding Guowen , Chen Ke , Qian Guangxu , Zhao Junming , Jiang Tian , Feng Yijun , Wang Zhengbin 
Published: May 2020

AbstractAlthough metasurfaces have provided unprecedented control of electromagnetic (EM) waves, it is still challenging for the arbitrary manipulation of spatial radiation modes, energy distribution, and spin state of EM wave especially in microwave frequencies. Here, a cascaded dual‐helicity‐decoupled transmissive metasurface to realize independent modulation of two orthogonal circularly polarized waves is proposed. Leveraging this appealing feature, distinct multiple beams with freely designed energy intensities for two spin states generated from a metasurface are demonstrated experimentally with high efficiency, providing full control of sophisticated wavefronts, spin states, and their energy allocations. Two proof‐of‐concept designs are implemented in microwave region, which may offer a new way to achieve spatially energy‐editable multifunctional devices that can be used in practical applications, such as beam forming, multiple target tracking, and wireless communications.