Pub Date : 2025-05-17DOI: 10.1021/acs.nanolett.5c00980
Logan Smith, Abdul Halim, K. Elena Harbison, Bibash Sapkota, Robert Klie, Benjamin T. Diroll, Igor Fedin
Short-wave infrared (SWIR) materials are highly beneficial in telecommunications and medical imaging. Synthesis of quality SWIR chromophores remains challenging. Furthermore, many SWIR-emitting colloidal quantum dots (QDs) suffer from long radiative lifetimes and weak emission efficiencies. To address these challenges, we present methods to create a size series of Cd3P2 QDs and create a sizing curve. The results demonstrate that the growth kinetics and the production of Cd3P2 QDs with optical emission at 1.5+ μm are limited by the precursor stoichiometry. To address the overly long radiative lifetimes, we develop surface passivation with CdI2 and develop a one-pot, hot-injection synthesis of (CdxZn1–x)3P2 QDs, which is shown to accelerate the PL dynamics of Cd3P2 QDs. Electron microscopy and elemental analysis point to the Cd3P2/(CdxZn1–x)3P2 core/crust structure of these QDs. These results show promise for the further development of core/shell Cd3P2/Zn3P2 QDs, which will serve as on-demand single-photon emitters in the SWIR region.
{"title":"Synthesis and Size-Dependent Optical Properties of Cd3P2 and (CdxZn1–x)3P2 Quantum Dots","authors":"Logan Smith, Abdul Halim, K. Elena Harbison, Bibash Sapkota, Robert Klie, Benjamin T. Diroll, Igor Fedin","doi":"10.1021/acs.nanolett.5c00980","DOIUrl":"https://doi.org/10.1021/acs.nanolett.5c00980","url":null,"abstract":"Short-wave infrared (SWIR) materials are highly beneficial in telecommunications and medical imaging. Synthesis of quality SWIR chromophores remains challenging. Furthermore, many SWIR-emitting colloidal quantum dots (QDs) suffer from long radiative lifetimes and weak emission efficiencies. To address these challenges, we present methods to create a size series of Cd<sub>3</sub>P<sub>2</sub> QDs and create a sizing curve. The results demonstrate that the growth kinetics and the production of Cd<sub>3</sub>P<sub>2</sub> QDs with optical emission at 1.5+ μm are limited by the precursor stoichiometry. To address the overly long radiative lifetimes, we develop surface passivation with CdI<sub>2</sub> and develop a one-pot, hot-injection synthesis of (Cd<sub><i>x</i></sub>Zn<sub>1–<i>x</i></sub>)<sub>3</sub>P<sub>2</sub> QDs, which is shown to accelerate the PL dynamics of Cd<sub>3</sub>P<sub>2</sub> QDs. Electron microscopy and elemental analysis point to the Cd<sub>3</sub>P<sub>2</sub>/(Cd<sub><i>x</i></sub>Zn<sub>1–<i>x</i></sub>)<sub>3</sub>P<sub>2</sub> core/crust structure of these QDs. These results show promise for the further development of core/shell Cd<sub>3</sub>P<sub>2</sub>/Zn<sub>3</sub>P<sub>2</sub> QDs, which will serve as on-demand single-photon emitters in the SWIR region.","PeriodicalId":53,"journal":{"name":"Nano Letters","volume":"97 1","pages":""},"PeriodicalIF":10.8,"publicationDate":"2025-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144067514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Previous investigations on the aging mechanism of solid electrolytes (SEs) predominantly focused on electrochemical and mechanical properties, often overlooking their thermal characteristics. In this study, we introduced scanning thermal microscopy and scanning thermo-ionic microscopy to delve into the microscopic aging process of the Li1.4Al0.4Ti1.6(PO4)3 (LATP) SE assembled with Li metal. Our findings revealed the formation of a Li3Al0.4Ti1.6(PO4)3 secondary phase during cycling. Compared with the unreacted LATP, this secondary phase exhibits a remarkable decrease in thermal conductivity (from 1.72 to 0.63 W m–1 K–1), Young’s modulus (from 117.4 to 31.3 GPa), and ionic activity, while demonstrating an increase in thermal expansion response. These mismatches worsen the interfacial contact, contributing to the formation of cracks and a sharp increase in impedance. To the best of our knowledge, this is the first time that the thermomechanical coupling of SEs has been studied at the nanoscale, underscoring the pivotal impact of the thermal properties on SE degradation.
以往对固体电解质老化机理的研究主要集中在电化学和力学性能方面，而忽视了其热特性。本研究采用扫描热显微镜和扫描热离子显微镜研究了Li金属组装Li1.4Al0.4Ti1.6(PO4)3 (LATP) SE的微观时效过程。结果表明，在循环过程中形成了Li3Al0.4Ti1.6(PO4)3次级相。与未反应的LATP相比，该二次相的导热系数（从1.72降至0.63 W m-1 K-1）、杨氏模量（从117.4降至31.3 GPa）和离子活性显著降低，而热膨胀响应则有所增加。这些不匹配使界面接触恶化，导致裂纹的形成和阻抗的急剧增加。据我们所知，这是第一次在纳米尺度上研究SE的热力耦合，强调了热性质对SE降解的关键影响。
{"title":"Nanoscale Thermomechanical Coupling Study on the Aging of NASICON-Type Solid Electrolytes","authors":"Xuyang Wang, Fang Wang, Qingfeng Zhu, Mingqiang Cheng, Chunlin Song, Yingzhi Li, Zhouguang Lu, Hongyun Jin, Boyuan Huang","doi":"10.1021/acs.nanolett.5c00971","DOIUrl":"https://doi.org/10.1021/acs.nanolett.5c00971","url":null,"abstract":"Previous investigations on the aging mechanism of solid electrolytes (SEs) predominantly focused on electrochemical and mechanical properties, often overlooking their thermal characteristics. In this study, we introduced scanning thermal microscopy and scanning thermo-ionic microscopy to delve into the microscopic aging process of the Li<sub>1.4</sub>Al<sub>0.4</sub>Ti<sub>1.6</sub>(PO<sub>4</sub>)<sub>3</sub> (LATP) SE assembled with Li metal. Our findings revealed the formation of a Li<sub>3</sub>Al<sub>0.4</sub>Ti<sub>1.6</sub>(PO<sub>4</sub>)<sub>3</sub> secondary phase during cycling. Compared with the unreacted LATP, this secondary phase exhibits a remarkable decrease in thermal conductivity (from 1.72 to 0.63 W m<sup>–1</sup> K<sup>–1</sup>), Young’s modulus (from 117.4 to 31.3 GPa), and ionic activity, while demonstrating an increase in thermal expansion response. These mismatches worsen the interfacial contact, contributing to the formation of cracks and a sharp increase in impedance. To the best of our knowledge, this is the first time that the thermomechanical coupling of SEs has been studied at the nanoscale, underscoring the pivotal impact of the thermal properties on SE degradation.","PeriodicalId":53,"journal":{"name":"Nano Letters","volume":"42 1","pages":""},"PeriodicalIF":10.8,"publicationDate":"2025-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144067515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-05-17DOI: 10.1021/acs.nanolett.5c01506
Xian-Kui Wei, Ke Xu, Kaushik Vaideeswaran, Joachim Mayer, Houbing Huang
Topological polar structures, in analogy to spin vortices and skyrmions, have received tremendous attention for their fascinating prospects in future device applications. However, in the widely studied ferroelectric-based superlattices, the epitaxial heterointerfaces, yielding desired strain, depolarization, and gradient energies, greatly confine the mobility of the topological solitons. Here, we report observation of polar vortex–antivortex pairs near junctions of antiphase boundaries in antiferroelectric PbZrO3 thin films by using atomic-resolution scanning transmission electron microscopy. Our temporal-resolved lattice analysis reveals that the local strain gradient caused by an incommensurate modulation constructs the smallest topological units reported to date. Our phase-field simulations unveil that the Pb–O vacancy-induced random electric fields account for their three-dimensional formation, and the stimulus of electron-beam irradiation can drive their dynamic migration. The findings offer a new approach to comprehend fundamental physics about antiferroelectricity and the design of functional devices based on topological structures in antiferroelectric thin films.
{"title":"Observation of Atomic-Scale Polar Vortex–Antivortex Pairs in Antiferroelectric PbZrO3 Thin Films","authors":"Xian-Kui Wei, Ke Xu, Kaushik Vaideeswaran, Joachim Mayer, Houbing Huang","doi":"10.1021/acs.nanolett.5c01506","DOIUrl":"https://doi.org/10.1021/acs.nanolett.5c01506","url":null,"abstract":"Topological polar structures, in analogy to spin vortices and skyrmions, have received tremendous attention for their fascinating prospects in future device applications. However, in the widely studied ferroelectric-based superlattices, the epitaxial heterointerfaces, yielding desired strain, depolarization, and gradient energies, greatly confine the mobility of the topological solitons. Here, we report observation of polar vortex–antivortex pairs near junctions of antiphase boundaries in antiferroelectric PbZrO<sub>3</sub> thin films by using atomic-resolution scanning transmission electron microscopy. Our temporal-resolved lattice analysis reveals that the local strain gradient caused by an incommensurate modulation constructs the smallest topological units reported to date. Our phase-field simulations unveil that the Pb–O vacancy-induced random electric fields account for their three-dimensional formation, and the stimulus of electron-beam irradiation can drive their dynamic migration. The findings offer a new approach to comprehend fundamental physics about antiferroelectricity and the design of functional devices based on topological structures in antiferroelectric thin films.","PeriodicalId":53,"journal":{"name":"Nano Letters","volume":"7 1","pages":""},"PeriodicalIF":10.8,"publicationDate":"2025-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144067516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-05-17DOI: 10.1021/acs.nanolett.5c01776
Chuang Shen, Xianghong Niu, Jianwei Chen, Fei Xu, Ming Liu, Yefan Duan, Hongfang Du, Qianshi Shang, Xiuyun Zhang, Ying Zhang, Lixing Weng, Zhimin Luo, Lianhui Wang
Radiodynamic therapy (RDT) holds great potential for overcoming radioresistance and enhancing tumor immunogenicity. However, its efficacy is hindered by limited reactive oxygen species (ROS) generation due to insufficient carrier generation and transfer, which often results in tumor metastasis. Here, we report quantum-sized and narrow-bandgap Sb@Au Schottky heterostructures, namely, Sb@Au nanodots (Sb@Au NDs), to improve ROS generation for sensitizing RDT and inhibiting tumor metastasis. Experimental results and density functional theory calculations show that Sb@Au NDs give narrow bandgap and high Schottky potential barrier for promoting carrier generation and separation under X-ray irradiation, and present rich active sites for improving catalytic performance, leading to abundant ROS generation and significantly amplifying intracellular oxidative stress to enhance RDT. Sb@Au ND-sensitized RDT greatly induces immunogenic cell death and thus promotes CD8+ T cell-mediated systemic immunity, ultimately suppressing tumor metastasis. Our finding highlights the potential of narrow-bandgap Sb@Au NDs as an effective sensitizer for radioimmunotherapy.
{"title":"Quantum-Sized Sb@Au Schottky Heterostructure for Sensitized Radioimmunotherapy","authors":"Chuang Shen, Xianghong Niu, Jianwei Chen, Fei Xu, Ming Liu, Yefan Duan, Hongfang Du, Qianshi Shang, Xiuyun Zhang, Ying Zhang, Lixing Weng, Zhimin Luo, Lianhui Wang","doi":"10.1021/acs.nanolett.5c01776","DOIUrl":"https://doi.org/10.1021/acs.nanolett.5c01776","url":null,"abstract":"Radiodynamic therapy (RDT) holds great potential for overcoming radioresistance and enhancing tumor immunogenicity. However, its efficacy is hindered by limited reactive oxygen species (ROS) generation due to insufficient carrier generation and transfer, which often results in tumor metastasis. Here, we report quantum-sized and narrow-bandgap Sb@Au Schottky heterostructures, namely, Sb@Au nanodots (Sb@Au NDs), to improve ROS generation for sensitizing RDT and inhibiting tumor metastasis. Experimental results and density functional theory calculations show that Sb@Au NDs give narrow bandgap and high Schottky potential barrier for promoting carrier generation and separation under X-ray irradiation, and present rich active sites for improving catalytic performance, leading to abundant ROS generation and significantly amplifying intracellular oxidative stress to enhance RDT. Sb@Au ND-sensitized RDT greatly induces immunogenic cell death and thus promotes CD8<sup>+</sup> T cell-mediated systemic immunity, ultimately suppressing tumor metastasis. Our finding highlights the potential of narrow-bandgap Sb@Au NDs as an effective sensitizer for radioimmunotherapy.","PeriodicalId":53,"journal":{"name":"Nano Letters","volume":"152 1","pages":""},"PeriodicalIF":10.8,"publicationDate":"2025-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144067330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-05-17DOI: 10.1021/acs.nanolett.5c00262
Marta Przychodnia, Maciej Bazarnik
In this study, we comprehensively analyze single and triple layers of a new two-dimensional surface alloy, namely DyPt2. Both are ferromagnetic materials with an in-plane easy magnetization axis and low Curie temperature on the order of a few Kelvins. Magnetic and electronic properties confirm weak interlayer coupling and the dominance of interactions within alloy layers. Atomic-scale investigation proved nearly the same atomic structure of the termination layer and varying moiré patterns. The electronic structures of single and triple layer DyPt2 are similar, consisting of a mixture of Dy and Pt electronic states. The intensity of these electronic states varies within the moiré pattern, similar to the surface local work function, demonstrating modulated coupling between the surface alloy and the substrate. The presented results provide essential knowledge for further research of this system in terms of its application in the growth of densely packed arrays of magnetic clusters and molecules.
{"title":"Ferromagnetism in Two-Dimensional Dysprosium–Platinum Surface Alloy","authors":"Marta Przychodnia, Maciej Bazarnik","doi":"10.1021/acs.nanolett.5c00262","DOIUrl":"https://doi.org/10.1021/acs.nanolett.5c00262","url":null,"abstract":"In this study, we comprehensively analyze single and triple layers of a new two-dimensional surface alloy, namely DyPt<sub>2</sub>. Both are ferromagnetic materials with an in-plane easy magnetization axis and low Curie temperature on the order of a few Kelvins. Magnetic and electronic properties confirm weak interlayer coupling and the dominance of interactions within alloy layers. Atomic-scale investigation proved nearly the same atomic structure of the termination layer and varying moiré patterns. The electronic structures of single and triple layer DyPt<sub>2</sub> are similar, consisting of a mixture of Dy and Pt electronic states. The intensity of these electronic states varies within the moiré pattern, similar to the surface local work function, demonstrating modulated coupling between the surface alloy and the substrate. The presented results provide essential knowledge for further research of this system in terms of its application in the growth of densely packed arrays of magnetic clusters and molecules.","PeriodicalId":53,"journal":{"name":"Nano Letters","volume":"16 1","pages":""},"PeriodicalIF":10.8,"publicationDate":"2025-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144067329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Efficient binding of cell membranes onto nanomaterials is essential for biomedical applications such as diagnostics and cellular engineering. We find that fine control over oligomer orientation led to enhanced electrostatic interactions with the cell membrane and improved cell membrane capture. Specifically, we designed polycation oligomers incorporating positively charged imidazole heads and alkyl tails synthesized through the reversible addition-fragmentation chain transfer (RAFT) reaction. These oligomers spontaneously self-assemble through head-to-head π-π interactions, and their spatial arrangement markedly accelerates the interaction with negatively charged cell membranes. Experimental results indicate that these oriented oligomers produce a large decrease in the time required to kill bacteria compared to unmodified nanostructures (3 min versus 100 min). This is attributed to locally concentrated electrostatic attraction, which enhances the attraction between nanostructures and negatively charged cell surfaces. Our findings suggest that molecular orientation control could be a promising approach to enhancing interactions between biomaterials and live cells.
{"title":"Precise Oligomer Organization Enhanced Electrostatic Interactions for Efficient Cell Membrane Binding.","authors":"Yuanyuan Zhao,Yiqian Luo,Yi Chai,Yintung Lam,Yongqing Gong,Ke Chen,Gang Lu,Gang Xia,Yun Chang,Menghao Yang,Yang Xu,John Haozhong Xin","doi":"10.1021/acs.nanolett.5c00651","DOIUrl":"https://doi.org/10.1021/acs.nanolett.5c00651","url":null,"abstract":"Efficient binding of cell membranes onto nanomaterials is essential for biomedical applications such as diagnostics and cellular engineering. We find that fine control over oligomer orientation led to enhanced electrostatic interactions with the cell membrane and improved cell membrane capture. Specifically, we designed polycation oligomers incorporating positively charged imidazole heads and alkyl tails synthesized through the reversible addition-fragmentation chain transfer (RAFT) reaction. These oligomers spontaneously self-assemble through head-to-head π-π interactions, and their spatial arrangement markedly accelerates the interaction with negatively charged cell membranes. Experimental results indicate that these oriented oligomers produce a large decrease in the time required to kill bacteria compared to unmodified nanostructures (3 min versus 100 min). This is attributed to locally concentrated electrostatic attraction, which enhances the attraction between nanostructures and negatively charged cell surfaces. Our findings suggest that molecular orientation control could be a promising approach to enhancing interactions between biomaterials and live cells.","PeriodicalId":53,"journal":{"name":"Nano Letters","volume":"15 1","pages":""},"PeriodicalIF":10.8,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144065776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-05-16DOI: 10.1021/acs.nanolett.5c01101
Calum Shelden, Benjamin Spreng, Joseph L. Garrett, Tahmid S. Rahman, Jongbum Kim, Jeremy N. Munday
The Casimir force dominates interactions between solid objects at sub-micrometer distances and typically limits the smallest distance between micromechanical devices before failure. Here, we experimentally circumvent this limitation by controlling the Casimir force with engineered 3D nanostructures. Using our recently developed method to align and measure the force between two microscale objects on the nanoscale, we characterized the force gradient between spheres and circular pillars, hollow cylinders, and periodic pillar arrays. We demonstrate that the force behavior can be dramatically modified in these geometries, resulting in a suppression of the Casimir force by 10× for a single pillar. We found agreement between theory and experiment, even when the size of the objects was comparable to the surface-to-surface separation (i.e., within a factor of ∼3). We anticipate that our results will impact the design of future micro- and nanoscale actuators, optomechanical devices with increased sensitivities and reduced stiction, and advanced bio-inspired adhesives.
{"title":"Casimir Force Control Enabled by 3D Nanostructures","authors":"Calum Shelden, Benjamin Spreng, Joseph L. Garrett, Tahmid S. Rahman, Jongbum Kim, Jeremy N. Munday","doi":"10.1021/acs.nanolett.5c01101","DOIUrl":"https://doi.org/10.1021/acs.nanolett.5c01101","url":null,"abstract":"The Casimir force dominates interactions between solid objects at sub-micrometer distances and typically limits the smallest distance between micromechanical devices before failure. Here, we experimentally circumvent this limitation by controlling the Casimir force with engineered 3D nanostructures. Using our recently developed method to align and measure the force between two microscale objects on the nanoscale, we characterized the force gradient between spheres and circular pillars, hollow cylinders, and periodic pillar arrays. We demonstrate that the force behavior can be dramatically modified in these geometries, resulting in a suppression of the Casimir force by 10× for a single pillar. We found agreement between theory and experiment, even when the size of the objects was comparable to the surface-to-surface separation (i.e., within a factor of ∼3). We anticipate that our results will impact the design of future micro- and nanoscale actuators, optomechanical devices with increased sensitivities and reduced stiction, and advanced bio-inspired adhesives.","PeriodicalId":53,"journal":{"name":"Nano Letters","volume":"42 1","pages":""},"PeriodicalIF":10.8,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144066286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Gold nanotetrapods (NTPs) possess sharp branched tips, high surface-to-volume ratios, and strong localized surface plasmon resonance in the near-infrared (NIR) region, making them candidates for biomedical applications. However, their practical use is limited by structural instability and inadequate biocompatibility in complex physiological environments. In this study, we developed an innovative in situ radical polymerization technique to encapsulate NTPs with a thin, cross-linked zwitterionic polymer shell, forming highly stable and biocompatible nanoparticles (NTP@XP). The polymer shell preserved the tetrapod structure and endowed NTPs with tunable surface properties through the polymerization of different monomers. Under NIR irradiation, NTP@XP exhibited enhanced photoacoustic imaging and a photothermal conversion performance in vitro. In vivo, the antifouling and biocompatible coating of NTP@XP allowed durable imaging and suppressed tumor regrowth in mice. This work establishes in situ polymerization as a robust strategy to stabilize NTPs, paving the way for various biomedical fields.
{"title":"Stabilizing Gold Nanotetrapods via in Situ Polymerization for Superior Photoacoustic and Photothermal Applications.","authors":"Jing Wang,Huazhen Chen,Dazhi Chen,Yuchao Luo,Zhi-Li Shen,Ning-Ning Zhang,Biqin Dong,Wenjing Tian,Kun Liu,Bin Xu","doi":"10.1021/acs.nanolett.5c01764","DOIUrl":"https://doi.org/10.1021/acs.nanolett.5c01764","url":null,"abstract":"Gold nanotetrapods (NTPs) possess sharp branched tips, high surface-to-volume ratios, and strong localized surface plasmon resonance in the near-infrared (NIR) region, making them candidates for biomedical applications. However, their practical use is limited by structural instability and inadequate biocompatibility in complex physiological environments. In this study, we developed an innovative in situ radical polymerization technique to encapsulate NTPs with a thin, cross-linked zwitterionic polymer shell, forming highly stable and biocompatible nanoparticles (NTP@XP). The polymer shell preserved the tetrapod structure and endowed NTPs with tunable surface properties through the polymerization of different monomers. Under NIR irradiation, NTP@XP exhibited enhanced photoacoustic imaging and a photothermal conversion performance in vitro. In vivo, the antifouling and biocompatible coating of NTP@XP allowed durable imaging and suppressed tumor regrowth in mice. This work establishes in situ polymerization as a robust strategy to stabilize NTPs, paving the way for various biomedical fields.","PeriodicalId":53,"journal":{"name":"Nano Letters","volume":"53 1","pages":""},"PeriodicalIF":10.8,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144065777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The development of quantum-dot light-emitting diodes (QLEDs) has been hindered by an incomplete understanding of their charge injection dynamics. This study systematically investigates electron-hole injection in red, green, and blue QLEDs using electrically pumped transient absorption and time-resolved electroluminescence technologies. Temperature-dependent measurements between 140 and 298 K reveal weak electron injection enhancement versus strong hole injection improvement as temperature increases. Therefore, lower temperatures exacerbate charge imbalance, increasing electron accumulation in quantum dots during the operation. We develop quantitative models using space-charge-limited current and thermionic emission theories for electron and hole injection, respectively, establishing a universal framework for QLED operation. These findings provide critical insights for optimizing the charge balance and device performance in QLEDs.
{"title":"Measurement and Modeling of Electron and Hole Injection Dynamics in Quantum-Dot Light-Emitting Diodes: Quantifying Temperature-Dependent Charge Imbalance.","authors":"Tianle Fan,Xitong Zhu,Shuai Chang,Xianchang Yan,Yizheng Jin,Shengye Jin,Boning Wu,Wenming Tian","doi":"10.1021/acs.nanolett.5c01227","DOIUrl":"https://doi.org/10.1021/acs.nanolett.5c01227","url":null,"abstract":"The development of quantum-dot light-emitting diodes (QLEDs) has been hindered by an incomplete understanding of their charge injection dynamics. This study systematically investigates electron-hole injection in red, green, and blue QLEDs using electrically pumped transient absorption and time-resolved electroluminescence technologies. Temperature-dependent measurements between 140 and 298 K reveal weak electron injection enhancement versus strong hole injection improvement as temperature increases. Therefore, lower temperatures exacerbate charge imbalance, increasing electron accumulation in quantum dots during the operation. We develop quantitative models using space-charge-limited current and thermionic emission theories for electron and hole injection, respectively, establishing a universal framework for QLED operation. These findings provide critical insights for optimizing the charge balance and device performance in QLEDs.","PeriodicalId":53,"journal":{"name":"Nano Letters","volume":"55 1","pages":""},"PeriodicalIF":10.8,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144065964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Spiking neural network (SNN) hardware relies on implicit assumptions that prioritize dendritic/synaptic learning above axon/synaptic concerns, compromising performances in signal capacity, accuracy, and compactness of SNN systems. Herein, we develop an artificial axon by utilizing the heterogeneity and interface state tunability in anisotropic two-dimensional (2D) tellurium (Te). By operating a multiterminal axon under the bioelectricity level, the device achieved neuron-like heterogeneous axon dynamics expansion (∼258%). An excellent dendritic-like tunability (∼197%) exhibits gain on the axons. The synergistic axon-dendrite optimization device exhibits 5-bit programmable conductance, signal filtering, and input enhancing. The accuracy of recognizing data sets based on the SNN algorithm demonstrates efficient optimization (5.2% higher accuracy) of networks by the device features, especially in the case of performing image preprocessing. This artificial neuron solution with anisotropic 2D materials utilizing biomimetic interface engineering provides a universal strategy for compact, high-precision parallel architecture of SNN hardware.
{"title":"Artificial Axon with Dendritic-like Plasticity by Biomimetic Interface Engineering of Anisotropic Two-Dimensional Tellurium.","authors":"Jiwei Chen,Changjian Zhou,Yingjie Luo,Wenbo Li,Xiankai Lin,Chunlei Zhang,Siyu Liao,Ruolan Wen,Guitian Qiu,Qian Zhang,Jianxian Yi,Wenhan Lei,Lin Wang,Syed Rizwan,Pei Lin,Qijie Liang","doi":"10.1021/acs.nanolett.5c01478","DOIUrl":"https://doi.org/10.1021/acs.nanolett.5c01478","url":null,"abstract":"Spiking neural network (SNN) hardware relies on implicit assumptions that prioritize dendritic/synaptic learning above axon/synaptic concerns, compromising performances in signal capacity, accuracy, and compactness of SNN systems. Herein, we develop an artificial axon by utilizing the heterogeneity and interface state tunability in anisotropic two-dimensional (2D) tellurium (Te). By operating a multiterminal axon under the bioelectricity level, the device achieved neuron-like heterogeneous axon dynamics expansion (∼258%). An excellent dendritic-like tunability (∼197%) exhibits gain on the axons. The synergistic axon-dendrite optimization device exhibits 5-bit programmable conductance, signal filtering, and input enhancing. The accuracy of recognizing data sets based on the SNN algorithm demonstrates efficient optimization (5.2% higher accuracy) of networks by the device features, especially in the case of performing image preprocessing. This artificial neuron solution with anisotropic 2D materials utilizing biomimetic interface engineering provides a universal strategy for compact, high-precision parallel architecture of SNN hardware.","PeriodicalId":53,"journal":{"name":"Nano Letters","volume":"1 1","pages":""},"PeriodicalIF":10.8,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144065787","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：