Nano Express最新文献

{"title":"Synthesis, characterization and magneto-structural properties of geometrical and compositional modulated nanowires","authors":"Ana Isabel Jiménez-Ramírez, Yolanda Álvarez López, Ana Silvia González, Javier García Fernández, Jose Ángel Fernández-Roldán, Víctor Vega Martínez, Miguel Méndez and Víctor M Prida","doi":"10.1088/2632-959x/ad5220","DOIUrl":"https://doi.org/10.1088/2632-959x/ad5220","url":null,"abstract":"The unique physicochemical properties of metallic and magnetic nanowires, whether obtained in well-ordered arrays or as single, isolated, and free-standing structures from patterned templates, have been extensively studied for various technological applications. These applications include magnetic data storage, sensing, biolabeling, barcoding, among many others. Novel template-assisted methods for the synthesis of metallic nanowires offer an enhancement over the control of their shape and morphology, compositional uniformity, and interconnectivity, allowing them for being applied as new metamaterials for novel multifunctional applications. Within this critical review, an extensive overview focused on the synthesis and characterization of the particular properties exhibited by multilayered and multisegmented metallic nanowires having specifically controlled geometries and compositional graded designs through employing electrochemical techniques based on sacrificial nanoporous alumina template-assisted methods, is presented. We review recent advancements in designing synthesis protocols for fabricating new metallic nanowires with multifunctional applications. These protocols offer competitive fabrication costs compared to conventional laboratory procedures, potentially expanding their use in various research areas. In this review, we also establish the new challenges and suggest the future perspectives and expectations that will be covered by these new metamaterial-based nanowires.","PeriodicalId":501827,"journal":{"name":"Nano Express","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142225409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A comparative study of broadband PbS quantum dots/graphene photodetectors with monolayer and bilayer graphene","authors":"Austin Olson, Dakeya Chambers, Sarah Gotfredson, Andrew Shultz, Bo Liu, Maogang Gong and Judy Z Wu","doi":"10.1088/2632-959x/ad6c6a","DOIUrl":"https://doi.org/10.1088/2632-959x/ad6c6a","url":null,"abstract":"Colloidal quantum dots (QDs)/graphene nanohybrids provide a unique platform to design photodetectors of high performance. These photodetectors are quantum sensors due to the strong quantum confinement in QDs for spectral tunability, and in graphene for high charge mobility. Quantitatively, the high carrier mobility of graphene plays a critical role to enable high photoconductive gain and understanding its impact on the photodetector performance is imperative. Herein, we report a comparative study of PbS QDs/graphene nanohybrids with monolayer and bilayer graphene for broadband photodetection ranging from ultraviolet, visible, near-infrared to short-wave infrared spectra (wavelength: 400 nm–1750 nm) to determine if a specific advantage exists for one over the other. This study has revealed that both the monolayer and bilayer graphene grown in chemical vapor deposition can provide a highly efficient charge transfer channel for photo-generated carriers for high broadband photoresponse.","PeriodicalId":501827,"journal":{"name":"Nano Express","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Occurrence of the collective Ziman limit of heat transport in cubic semiconductors Si, Ge, AlAs and AlP: scattering channels and size effects","authors":"Jelena Sjakste, Maxime Markov, Raja Sen, Giorgia Fugallo, Lorenzo Paulatto, Nathalie Vast","doi":"10.1088/2632-959x/ad70cf","DOIUrl":"https://doi.org/10.1088/2632-959x/ad70cf","url":null,"abstract":"In this work, we discuss the possibility of reaching the Ziman conditions for collective heat transport in cubic bulk semiconductors, such as Si, Ge, AlAs and AlP. In natural and enriched silicon and germanium, the collective heat transport limit is impossible to reach due to strong isotopic scattering. However, we show that in hyper-enriched silicon and germanium, as well as in materials with one single stable isotope like AlAs and AlP, at low temperatures, normal scattering plays an important role, making the observation of the collective heat transport possible. We further discuss the effects of sample sizes, and analyse our results for cubic materials by comparing them to bulk bismuth, in which second sound has been detected at cryogenic temperatures. We find that collective heat transport in cubic semiconductors studied in this work is expected to occur at temperatures between 10 and 20 K.","PeriodicalId":501827,"journal":{"name":"Nano Express","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142225424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structure and optical properties of ZnxCd1-xS and Cu:ZnxCd1-xS templated on DNA molecules","authors":"Andres Aldana, Andrew Houlton, Benjamin R Horrocks","doi":"10.1088/2632-959x/ad6f32","DOIUrl":"https://doi.org/10.1088/2632-959x/ad6f32","url":null,"abstract":"One-dimensional Zn_xCd_1−xS and Cu: Zn_{\u0000<italic toggle=\"yes\">x</italic>\u0000}Cd_{1−<italic toggle=\"yes\">x</italic>\u0000}S nanostructures were prepared using DNA as a template to promote growth along the molecular axis. The formation of homogeneously alloyed nanocrystals with cubic zinc blende-type structures was verified using x-ray diffraction and Raman spectroscopy. X-ray photoemission spectra revealed the presence of Cu(I) in the doped Cu: Zn_{\u0000<italic toggle=\"yes\">x</italic>\u0000}Cd_{1−<italic toggle=\"yes\">x</italic>\u0000}S nanocrystals. The effectiveness of the DNA template to direct the semiconductor growth in one dimension was demonstrated by AFM and TEM. The nanostructures displayed a granular morphology comprising nanoparticles with an average diameter of 14 nm composed of assemblies of smaller crystallites of 2.0 nm in size. Rope-like assemblies with an average diameter of 48 nm and extending in length to several hundred micrometres were obtained by evaporation-induced self-assembly. UV-Vis absorption and emission spectra indicated that the optical bandgaps (2.89–4.00eV) and photoluminescence peaks (608–819 nm) of the DNA-templated nanocrystals could be precisely controlled by modifying the molar ratios of their Zn/Cd precursors. Doping with Cu(I) gave an increase in photoluminescence intensity and a composition-independent red-shift of 0.23 eV. The preparation of DNA-templated Zn_{\u0000<italic toggle=\"yes\">x</italic>\u0000}Cd_{1−<italic toggle=\"yes\">x</italic>\u0000}S and Cu: Zn_{\u0000<italic toggle=\"yes\">x</italic>\u0000}Cd_{1−<italic toggle=\"yes\">x</italic>\u0000}S provides a simple, low-temperature route to aqueous dispersions of inorganic materials with controlled optical gap.","PeriodicalId":501827,"journal":{"name":"Nano Express","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142225410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electrochemical detection of sulfite using gold nanoparticles decorated poly[2-(methacryloyloxy) ethyl] trimethylammonium chloride: kinetic and mechanistic studies","authors":"Abdul Awal, Md Mithu Mia, Fahima Ferdaus, Md Abdul Kabir Hossain, S M Abu Nayem, Syed Shaheen Shah, M Nasiruzzaman Shaikh, Mohammad Abu Jafar Mazumder, Md Abdul Aziz, A J Saleh Ahammad","doi":"10.1088/2632-959x/ad6f31","DOIUrl":"https://doi.org/10.1088/2632-959x/ad6f31","url":null,"abstract":"Sulfites (SO₃\u0000²⁻) are widely used in various industries as a preservative in beverages, pharmaceutical products, wines, foods, and cosmetics. As a preservative, it prevents foods from spoiling and is also used as a bleaching agent due to its antioxidant, anti-browning, and antibacterial activity. Despite its widespread use, inhalation of SO₃\u0000²⁻ can lead to health issues such as headaches, nausea, asthma, dizziness, and reduction of red blood cells. Thus, accurate and efficient detection of sulfite is crucial. The deployment of positively charged poly [2-(methacryloyloxy) ethyl] trimethylammonium chloride (PMTC) decorated with gold nanoparticles (AuNPs) offers a novel approach, enhancing sensitivity and specificity in the electrochemical detection of negatively charged sulfite ions (SO₃\u0000²⁻). A sensor for detecting SO₃\u0000²⁻ was developed using PMTC decorated with AuNPs on a glassy carbon electrode (GCE). Transmission electron microscopy (TEM) was employed to examine the structural morphology of the composite material, and the formation of AuNPs was confirmed through ultraviolet-visible spectroscopy. Zeta potential analysis affirmed the positive charge of the PMTC composite, highlighting its effective coordination with the negatively charged SO₃\u0000²⁻. The surface conductivity of the modified GCE was studied using electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). Kinetic analyses, focusing on scan rate and pH dependencies, elucidated the SO₃\u0000²⁻ oxidation dynamics and the interaction between the positively charged PMTC and negatively charged SO₃\u0000²⁻. Quantitative evaluation was performed using the current–time (I-t) technique, achieving a limit of detection of 0.41 ± 0.003 μM (S/N = 3) within a linear range of 6.66 μM to 1020 μM. The modified electrode demonstrated remarkable stability, repeatability, and resistance to common interferents. Real sample analysis using laboratory tap water with a fixed SO₃\u0000²⁻ concentration exhibited excellent recovery. The oxidation of SO₃\u0000²⁻ on the AuNPs-PMTC-GCE proceeded via first-order kinetics and followed a stepwise pathway facilitated by the charge interactions.","PeriodicalId":501827,"journal":{"name":"Nano Express","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142225422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lycium ruthenicum stem extract mediated green synthesis of MnO2/Mn3(PO4)2 composite nanowire electrocatalyst for oxygen evolution reaction","authors":"Raj Kumar, Ritu Raj, Imtiaz Ahmed, Vikash Kumar, Gajendra Prasad Singh, Krishna Kanta Haldar","doi":"10.1088/2632-959x/ad70d0","DOIUrl":"https://doi.org/10.1088/2632-959x/ad70d0","url":null,"abstract":"A composite of manganese oxide (MnO₂) and Mn₃(PO₄)₂ decorated nanowires (MnO₂/Mn₃(PO₄)₂) was prepared using <italic toggle=\"yes\">Lycium ruthenicum</italic> stem-extract mediated green synthesis. This composite material functions as an efficient and long-lasting electrocatalyst for water-splitting reactions, which could significantly improve the performance of oxygen evolution reaction (OER). The OER activity of MnO₂/Mn₃(PO₄)₂-based nanowires is boosted by blending with a conducting support, such as manganese oxide (MnO₂). The x-ray diffraction pattern and Fourier transform infrared data indicate that the nanowires are highly crystalline. The MnO₂/Mn₃(PO₄)₂ composite material demonstrates superior stability compared to its individual constituents and generates a current density of 10 mA cm⁻² at a low overpotential of 244 mV for OER in alkaline media. This research may lead to the development of MnO₂/Mn₃(PO₄)₂ composite materials as electrocatalysts for overall water-splitting reactions.","PeriodicalId":501827,"journal":{"name":"Nano Express","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hybrid deep learning for design of nanophotonic quantum emitter lenses","authors":"Didulani Acharige, Eric Johlin","doi":"10.1088/2632-959x/ad6e09","DOIUrl":"https://doi.org/10.1088/2632-959x/ad6e09","url":null,"abstract":"Inverse design of nanophotonic structures has allowed unprecedented control over light. These design processes however are accompanied with challenges, such as their high sensitivity to initial conditions, computational expense, and complexity in integrating multiple design constraints. Machine learning approaches, however, show complementary strengths, allowing huge sample sets to be generated nearly instantaneously, and with transfer learning, allowing modifications in design parameters to be integrated with limited retraining. Herein we investigate a hybrid deep learning approach, leveraging the accuracy and performance of adjoint-based topology optimization to produce a high-quality training set for a convolutional generative network. We specifically explore this in the context of 3D nanophotonic lenses, used for focusing light between plane-waves and single-point, single-wavelength sources such as quantum emitters. We demonstrate that this combined approach allows higher performance than adjoint optimization alone when additional design constraints are applied; can generate large datasets (which further allows faster iterative training to be performed); and can utilize transfer learning to be retrained on new design parameters with very few new training samples. This process can be used for general nanophotonic design, and is particularly beneficial when a range of design parameters and constraints would need to be applied.","PeriodicalId":501827,"journal":{"name":"Nano Express","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"UV electromagnetic irradiation sensing by GQDs sensitized ZnO/GaN heterostructure for wearable dosimetry","authors":"Lalit Goswami, Pukhraj Prajapat, Pargam Vashishtha, Govind Gupta","doi":"10.1088/2632-959x/ad6c68","DOIUrl":"https://doi.org/10.1088/2632-959x/ad6c68","url":null,"abstract":"Sensing of Ultraviolet (UV) Electromagnetic Irradiations (EIs) for wearable dosimetry is promulgated universally by reserving their place in precise calibration for the controlled exposure of UV-EIs for the betterment of humankind. In other words, the controlled exposure of incident optical power density (OPD) of UV-EIs found advantageous and numerous noble healthcare applications such as beta-endorphin molecule (provide feel-good factor to the brain) level augmentation, adequate vitamin D (physical strength) level formation, in skin treatment like eczema and dermatitis, sensing important biomolecules like Uric Acid (responsible for critical disease related with kidney and heart). Moreover, the controlled exposure of OPDs also significantly impacts UV disinfection technologies, which provide a defensive shield against critical respiratory syndrome coronavirus 2 (SARS-CoV-2), which belongs to the COVID-19 pandemic. Therefore, by understanding the importance of limited exposure to these vital UV-EIs, the present study showcased the GQDs-sensitized ZnO/GaN heterostructured UV sensor utilized to explore the impact of UV-EIs OPDs on their performance. This study helps to develop and utilize the UV sensor-based wearable dosimetry for in-house diagnostics of critical healthcare parameters. This report also divulged an interesting core mechanism (band bending, tunneling through narrowed hole injection under increased negative bias) involved in affecting the performance of the UV-EIs sensor by a function of growing OPDs with the help of a suitable band diagram. The impact of increasing OPDs on fabricated UV-EIs sensors can be well understood by the fact that, by varying the OPDs up to ∼550%, the Gain (G), responsivity (R), external quantum efficiency (EQE) and noise equivalent power (NEP) significantly increases up to (156.7 to 332.4) ∼300%, (118 A W⁻¹ to 3200 A W⁻¹) 2700%, (∼870% to 12 × 10³%) 1400% and (1.3 pWHz^−1/2 to 50 fWHz^−1/2) 10,000% respectively at an applied bias of −6 V. Furthermore, the time-correlated transient photoresponse is also dramatically improved with increasing OPDs, wherein the increment in rise and decay time is estimated as (159 ms to 7.86 ms) ∼2000% and (68.7 ms to 12.4 ms) ∼500%, respectively.","PeriodicalId":501827,"journal":{"name":"Nano Express","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142225423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Persistent polarization effects and memory properties in ionic-liquid gated InAs nanowire transistors","authors":"Valeria Demontis, Domenic Prete, Enver Faella, Filippo Giubileo, Valentina Zannier, Ofelia Durante, Lucia Sorba, Antonio Di Bartolomeo, Francesco Rossella","doi":"10.1088/2632-959x/ad6581","DOIUrl":"https://doi.org/10.1088/2632-959x/ad6581","url":null,"abstract":"Iontronics exploits mobile ions within electrolytes to control the electronic properties of materials and devices' electrical and optical response. In this frame, ionic liquids are widely exploited for the gating of semiconducting nanostructure devices, offering superior performance compared to conventional dielectric gating. In this work, we engineer ionic liquid gated InAs nanowire-based field effect transistors and adopt the set-and-freeze dual gate device operation to probe the nanowires in several ionic gate regimes. We exploit standard back-gating at 150 K, when the ionic liquid is frozen and any crosstalk between the ionic gate and the back gate is ruled out. We demonstrate that the liquid gate polarization has a persistent effect on the nanowire properties. This effect can be conveniently exploited to fine-tune the properties of the nanowires and enable new device functionalities. Specifically, we correlate the modification of the ionic environment around the nanowire to the transistor threshold voltage and hysteresis, on/off ratio and current level retention times. Based on this, we demonstrate memory operations of the nanowire field effect transistors. Our work shines a new light on the interaction between electrolytes and semiconducting nanostructures, providing useful insights for future applications of nanodevice iontronics.","PeriodicalId":501827,"journal":{"name":"Nano Express","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141867496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tbx-Zn1-x-BDC MOF films synthesized in-situ by the aero-sol-assisted chemical vapor deposition","authors":"Julio Cesar Espinoza Tapia, Luis Alberto Becerril Landero, Enrique Barrera Calva, Juan Gabriel Vigueras Ramírez, Leonardo González-Reyes, Ciro Falcony-Guajardo","doi":"10.1088/2632-959x/ad6835","DOIUrl":"https://doi.org/10.1088/2632-959x/ad6835","url":null,"abstract":"\u0000 Tbx-Zn1-x-BDC MOF films were deposited in-situ on glass substrates by the aerosol-assisted chemical vapor deposition technique (AACVD) using an ultrasonic spray pyrolysis system, with x in the range of 0 to 1. Different precursors and solvents were used for the precursor solutions, which were deposited on a substrate using a controlled nebulization system. The obtained films were characterized using techniques, such as X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR) and photoluminescence spectroscopy. The results revealed the evolution of the Zn-BDC and/or Tb-BDC crystalline structures in the films, as well as the changes in the physical properties of the Metal-organic frameworks (MOFs) such as thickness and roughness of the films. Furthermore, these findings provide important information for the design and control of MOF films with specific properties and their potential application in various fields.","PeriodicalId":501827,"journal":{"name":"Nano Express","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141797093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}