Charge-transfer doping provides a nondestructive route to tune two-dimensional transition-metal dichalcogenides (TMDs), but selectively patterned n-type dopants effective across different TMD channels remain limited. Here, ultrathin bismuth oxide (BiOx) is used as an n-type charge-transfer doping and passivation layer for monolayer MoS2 and WSe2 transistors. In MoS2, 2 nm BiOx preserves the channel structure and yields a TLM-extracted effective contact resistance of 0.71 ± 0.06 kΩ·μm at n2D = 1.8 × 1013 cm–2. Thicker BiOx strengthens n-type modulation but reduces gate controllability. The modulation remains stable after ambient storage and air annealing. BiOx also enhances electron transport in WSe2 and enables homogeneous WSe2 inverters with MoOx-doped p-FETs, achieving a gain of ∼19 and a total normalized noise margin of 0.895 VDD at VDD = 2 V. These results establish BiOx as a cross-TMD n-type charge-transfer dopant for contact, threshold-voltage, and polarity engineering.
{"title":"Ultrathin BiOx Charge-Transfer Doping for Cross-TMD Electronic Modulation and Homogeneous WSe2 Inverters","authors":"Ching-Hao Hsu,Yu-Wei Hsu,Ta-Wei Hsu,Yu-Tung Lin,Li-Ya Chiu,I-Chih Ni,Chih-I Wu","doi":"10.1021/acs.nanolett.6c03585","DOIUrl":"https://doi.org/10.1021/acs.nanolett.6c03585","url":null,"abstract":"Charge-transfer doping provides a nondestructive route to tune two-dimensional transition-metal dichalcogenides (TMDs), but selectively patterned n-type dopants effective across different TMD channels remain limited. Here, ultrathin bismuth oxide (BiOx) is used as an n-type charge-transfer doping and passivation layer for monolayer MoS2 and WSe2 transistors. In MoS2, 2 nm BiOx preserves the channel structure and yields a TLM-extracted effective contact resistance of 0.71 ± 0.06 kΩ·μm at n2D = 1.8 × 1013 cm–2. Thicker BiOx strengthens n-type modulation but reduces gate controllability. The modulation remains stable after ambient storage and air annealing. BiOx also enhances electron transport in WSe2 and enables homogeneous WSe2 inverters with MoOx-doped p-FETs, achieving a gain of ∼19 and a total normalized noise margin of 0.895 VDD at VDD = 2 V. These results establish BiOx as a cross-TMD n-type charge-transfer dopant for contact, threshold-voltage, and polarity engineering.","PeriodicalId":53,"journal":{"name":"Nano Letters","volume":"73 1","pages":""},"PeriodicalIF":10.8,"publicationDate":"2026-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149218890","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 : 2026-10-19DOI: 10.1021/acs.nanolett.6c03830
Ami Hayakawa,Tetsu Tatsuma,Hiroyasu Nishi
Chiral nanostructures have attracted considerable attention because of their strong interactions with circularly polarized light (CPL) and their various applications. Although various fabrication methods have been reported, photoelectrochemical approaches using CPL as the chiral source are attractive because of their simplicity, cost-effectiveness, and scalability. However, previous CPL-based methods have required two or more steps, including the preparation of anisotropic precursors. Here, we demonstrate a single-step method for the selective growth of chiral PbO2 nanostructures with handedness dictated by CPL at a chiral yield of 87%, by simply irradiating a transparent electrode with CPL, without using precursor nanoparticles. The obtained structures exhibit well-defined spiral morphologies and high chiroptical activity with maximum dissymmetry factors (g-factors) ranging from 0.006 to 0.010. This conceptual framework, involving symmetry breaking through random nucleation and Mie-resonance-mediated spiral growth under CPL, may be applicable to the template-free fabrication of various chiral nanomaterials.
{"title":"Precursor-Free Photoelectrochemical Fabrication of Spiral Lead Oxide Nanostructures under Circularly Polarized Light","authors":"Ami Hayakawa,Tetsu Tatsuma,Hiroyasu Nishi","doi":"10.1021/acs.nanolett.6c03830","DOIUrl":"https://doi.org/10.1021/acs.nanolett.6c03830","url":null,"abstract":"Chiral nanostructures have attracted considerable attention because of their strong interactions with circularly polarized light (CPL) and their various applications. Although various fabrication methods have been reported, photoelectrochemical approaches using CPL as the chiral source are attractive because of their simplicity, cost-effectiveness, and scalability. However, previous CPL-based methods have required two or more steps, including the preparation of anisotropic precursors. Here, we demonstrate a single-step method for the selective growth of chiral PbO2 nanostructures with handedness dictated by CPL at a chiral yield of 87%, by simply irradiating a transparent electrode with CPL, without using precursor nanoparticles. The obtained structures exhibit well-defined spiral morphologies and high chiroptical activity with maximum dissymmetry factors (g-factors) ranging from 0.006 to 0.010. This conceptual framework, involving symmetry breaking through random nucleation and Mie-resonance-mediated spiral growth under CPL, may be applicable to the template-free fabrication of various chiral nanomaterials.","PeriodicalId":53,"journal":{"name":"Nano Letters","volume":"46 1","pages":""},"PeriodicalIF":10.8,"publicationDate":"2026-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149218893","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 : 2026-10-19DOI: 10.1021/acs.nanolett.6c03077
Ankita Bora,Suvodeep Sen,Niraj Nitish Patil,Temilade Esther Edgoke,Kevin M. Ryan,Shalini Singh
High-entropy chalcogenides represent an emerging class of functional materials with immense potential in broad applications. To date, colloidal high-entropy nanocrystals (NCs) have predominantly been accessed via co-nucleation of precursors or simultaneous incorporation of multiple cations. While effective, these approaches lack a mechanistic understanding of NC synthesis. Here, we report the colloidal synthesis of high-entropy Cu–Zn–Sb–Ag–Bi–S NCs in the tetrahedrite phase, employing a sequential, low-temperature cation-exchange strategy, starting from a Cu–Zn–Sb–S tetrahedrite template. Subsequent sequential cation exchanges preserve the crystal phase while enabling precise control over morphology. This bottom-up approach circumvents the need for high-temperature synthesis, while allowing isolation and characterization of intermediate states, providing important mechanistic insight into the evolution of high-entropy NCs. The nanocrystals served as hydrogen evolution reaction electrocatalysts with less negative cathodic potentials. This work introduces the high-entropy tetrahedrite phase, paving the way for entropy-stabilized chalcogenides for energy conversion applications.
{"title":"Engineering High-Entropy Tetrahedrite Cu–Zn–Sb–Ag–Bi–S Nanocrystals via Sequential Cation Exchange as Efficient Catalysts for Hydrogen Evolution Reactions","authors":"Ankita Bora,Suvodeep Sen,Niraj Nitish Patil,Temilade Esther Edgoke,Kevin M. Ryan,Shalini Singh","doi":"10.1021/acs.nanolett.6c03077","DOIUrl":"https://doi.org/10.1021/acs.nanolett.6c03077","url":null,"abstract":"High-entropy chalcogenides represent an emerging class of functional materials with immense potential in broad applications. To date, colloidal high-entropy nanocrystals (NCs) have predominantly been accessed via co-nucleation of precursors or simultaneous incorporation of multiple cations. While effective, these approaches lack a mechanistic understanding of NC synthesis. Here, we report the colloidal synthesis of high-entropy Cu–Zn–Sb–Ag–Bi–S NCs in the tetrahedrite phase, employing a sequential, low-temperature cation-exchange strategy, starting from a Cu–Zn–Sb–S tetrahedrite template. Subsequent sequential cation exchanges preserve the crystal phase while enabling precise control over morphology. This bottom-up approach circumvents the need for high-temperature synthesis, while allowing isolation and characterization of intermediate states, providing important mechanistic insight into the evolution of high-entropy NCs. The nanocrystals served as hydrogen evolution reaction electrocatalysts with less negative cathodic potentials. This work introduces the high-entropy tetrahedrite phase, paving the way for entropy-stabilized chalcogenides for energy conversion applications.","PeriodicalId":53,"journal":{"name":"Nano Letters","volume":"73 1","pages":""},"PeriodicalIF":10.8,"publicationDate":"2026-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149218948","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}
Multifocal phase holography offers a route to parallel femtosecond laser micro- and nanofabrication, but conventional weighted Gerchberg–Saxton (GSW) phase retrieval requires target-specific iterations and does not jointly optimize the optical quantities governing exposure quality. Here we introduce PhyFlow, a physics-consistent invertible flow model that generates phase-only multifocal holograms from target multifocal patterns in a single inverse pass. A multiscale invertible backbone learns target-to-phase correspondence, while differentiable Fourier optics constraints optimize diffraction efficiency, focal uniformity, and target-shape preservation. Across focal numbers and array scales, PhyFlow matches or surpasses GSW in energy concentration, focal balance, and shape fidelity while reducing per-hologram generation time by 98.8%. Optical-field measurements and femtosecond laser writing further show improved dot-area consistency, narrower line width distributions, and fewer nontarget written features. PhyFlow therefore connects rapid learned hologram generation with physically optimized fields and more uniform parallel fabrication.
{"title":"Physics-Consistent Generative Hologram Design for Multifocal Femtosecond Laser Fabrication","authors":"Bowen Chen,Hao Wu,Xiaoxu Rao,Wenji Yang,Zeye Li,Jincheng Ni,Jiawen Li,Dong Wu,Yanlei Hu,Chaowei Wang","doi":"10.1021/acs.nanolett.6c03779","DOIUrl":"https://doi.org/10.1021/acs.nanolett.6c03779","url":null,"abstract":"Multifocal phase holography offers a route to parallel femtosecond laser micro- and nanofabrication, but conventional weighted Gerchberg–Saxton (GSW) phase retrieval requires target-specific iterations and does not jointly optimize the optical quantities governing exposure quality. Here we introduce PhyFlow, a physics-consistent invertible flow model that generates phase-only multifocal holograms from target multifocal patterns in a single inverse pass. A multiscale invertible backbone learns target-to-phase correspondence, while differentiable Fourier optics constraints optimize diffraction efficiency, focal uniformity, and target-shape preservation. Across focal numbers and array scales, PhyFlow matches or surpasses GSW in energy concentration, focal balance, and shape fidelity while reducing per-hologram generation time by 98.8%. Optical-field measurements and femtosecond laser writing further show improved dot-area consistency, narrower line width distributions, and fewer nontarget written features. PhyFlow therefore connects rapid learned hologram generation with physically optimized fields and more uniform parallel fabrication.","PeriodicalId":53,"journal":{"name":"Nano Letters","volume":"414 1","pages":""},"PeriodicalIF":10.8,"publicationDate":"2026-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149218888","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 : 2026-10-19DOI: 10.1021/acs.nanolett.6c04201
Christina Boukouvala,Andrey Ten,Vladimir Lomonosov,Emilie Ringe
Magnesium, a promising alternative for sustainable nanophotonics, crystallizes in a hexagonal close-packed (HCP) system, unlike the face-centered cubic (FCC) structures of gold, silver, copper, and aluminum. We report the high-yield colloidal synthesis of an unexpected shape in an HCP system: cubes. Nanocubes with narrow size distributions were produced from colloidal reduction of a magnesium precursor in the presence of a sodium salt nucleating agent. Electron microscopy and diffraction reveal multiple twinning leading to the formation of six single-crystal units within the nanocubes. A self-limiting, sub-10 nm passivating oxide layer protects the metallic core against further oxidation in air and organic solvents. Strong, multimode plasmonic responses were observed using bulk extinction spectroscopy, single-particle scattering correlated with electron microscopy, and electron energy loss spectroscopy; experimental results were corroborated by numerical simulations. These findings expand the crystallographic boundaries of non-FCC plasmonics and establish magnesium nanocubes as versatile building blocks for nanophotonic applications.
{"title":"Squaring the Hexagon: Multiply Twinned Plasmonic Magnesium Nanocubes","authors":"Christina Boukouvala,Andrey Ten,Vladimir Lomonosov,Emilie Ringe","doi":"10.1021/acs.nanolett.6c04201","DOIUrl":"https://doi.org/10.1021/acs.nanolett.6c04201","url":null,"abstract":"Magnesium, a promising alternative for sustainable nanophotonics, crystallizes in a hexagonal close-packed (HCP) system, unlike the face-centered cubic (FCC) structures of gold, silver, copper, and aluminum. We report the high-yield colloidal synthesis of an unexpected shape in an HCP system: cubes. Nanocubes with narrow size distributions were produced from colloidal reduction of a magnesium precursor in the presence of a sodium salt nucleating agent. Electron microscopy and diffraction reveal multiple twinning leading to the formation of six single-crystal units within the nanocubes. A self-limiting, sub-10 nm passivating oxide layer protects the metallic core against further oxidation in air and organic solvents. Strong, multimode plasmonic responses were observed using bulk extinction spectroscopy, single-particle scattering correlated with electron microscopy, and electron energy loss spectroscopy; experimental results were corroborated by numerical simulations. These findings expand the crystallographic boundaries of non-FCC plasmonics and establish magnesium nanocubes as versatile building blocks for nanophotonic applications.","PeriodicalId":53,"journal":{"name":"Nano Letters","volume":"10 1","pages":""},"PeriodicalIF":10.8,"publicationDate":"2026-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149218891","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 : 2026-10-17DOI: 10.1021/acs.nanolett.6c04105
Ziyan Zhang,Yuhua Chen,Hongchao Yang,Yejun Zhang,Jiang Jiang,Yuliang Zhao,Xingwang Zhang,Qiangbin Wang
Abstract Solution-processable quantum dot (QD) lasers are essential for next-generation integrated photonic circuits, ranging, and optical sensing. However, their practical deployment remains hampered by high lasing thresholds. Here, we report AgAuSe QD lasing with a record-low threshold of 0.01 μJ cm–2 at 900 nm, representing a reduction of more than 4 orders of magnitude compared to those of previous near-infrared (NIR) QD lasing reports. This achievement is enabled by a well-designed twisted-lattice photonic crystal (PhC) nanocavity delivering extreme light confinement with an ultrahigh quality (Q) factor. The extended photon lifetime reduces the required gain volume, enabling lasing from a single-layer self-assembled QD superlattice (SL), which minimizes scattering losses. Crucially, the robust system allows us to push the operational regime to quasi-continuous-wave (q-CW) lasing at room temperature. These results establish a new benchmark for solution-processed NIR QD sources and provide a technologically viable pathway for sustained CW operation.
{"title":"Ultralow-Threshold\u0000NIR AgAuSe Colloidal Quantum Dot\u0000Laser","authors":"Ziyan Zhang,Yuhua Chen,Hongchao Yang,Yejun Zhang,Jiang Jiang,Yuliang Zhao,Xingwang Zhang,Qiangbin Wang","doi":"10.1021/acs.nanolett.6c04105","DOIUrl":"https://doi.org/10.1021/acs.nanolett.6c04105","url":null,"abstract":"Abstract Solution-processable quantum dot (QD) lasers are essential for next-generation integrated photonic circuits, ranging, and optical sensing. However, their practical deployment remains hampered by high lasing thresholds. Here, we report AgAuSe QD lasing with a record-low threshold of 0.01 μJ cm–2 at 900 nm, representing a reduction of more than 4 orders of magnitude compared to those of previous near-infrared (NIR) QD lasing reports. This achievement is enabled by a well-designed twisted-lattice photonic crystal (PhC) nanocavity delivering extreme light confinement with an ultrahigh quality (Q) factor. The extended photon lifetime reduces the required gain volume, enabling lasing from a single-layer self-assembled QD superlattice (SL), which minimizes scattering losses. Crucially, the robust system allows us to push the operational regime to quasi-continuous-wave (q-CW) lasing at room temperature. These results establish a new benchmark for solution-processed NIR QD sources and provide a technologically viable pathway for sustained CW operation.","PeriodicalId":53,"journal":{"name":"Nano Letters","volume":"69 2 1","pages":""},"PeriodicalIF":10.8,"publicationDate":"2026-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149210018","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}