Light emission via inelastic tunneling electrons is appealing for integrated optoelectronic devices due to its femtosecond time scale that can in principle allow terahertz modulation bandwidth. It has gained renewed interest since 2015 due to the improved quantum efficiency, highly tunable emission wavelength, linewidth, or directionality once the electrodes are designed as a plasmonic nanocavity. However, efficient construction of stable tunnel junctions with desired plasmonic resonances is still technically challenging because of the subnanometer precision required in the electrical and optical design. Here, we demonstrate an easily accessible electrically driven cavity plasmon in metal-insulator-metal (MIM) tunnel junctions, comprised by a Au nanowire (NW) across two separate ultrasmooth Au electrodes. Two layers of self-assembled thiol molecule defines a reliable tunneling barrier. The contribution from the localized cavity plasmons to the total light emission is found to be dominant over that from the propagating surface plasmon polariton in the MIM waveguide, different from the traditional explanations. This work introduces a simplified method for constructing electrically driven cavity plasmons using crystalline metals, which holds promise for applications in in-situ chemical or biosensing and the development of flexible light-emitting metasurfaces.
{"title":"Electrically driven cavity plasmons in Au nanowire over Au film","authors":"Junhao Zhang, Yu Wu, Wenna Zhou, Jibo Tang, Shunping Zhang, Hongxing Xu","doi":"10.1088/2632-959x/ad6836","DOIUrl":"https://doi.org/10.1088/2632-959x/ad6836","url":null,"abstract":"\u0000 Light emission via inelastic tunneling electrons is appealing for integrated optoelectronic devices due to its femtosecond time scale that can in principle allow terahertz modulation bandwidth. It has gained renewed interest since 2015 due to the improved quantum efficiency, highly tunable emission wavelength, linewidth, or directionality once the electrodes are designed as a plasmonic nanocavity. However, efficient construction of stable tunnel junctions with desired plasmonic resonances is still technically challenging because of the subnanometer precision required in the electrical and optical design. Here, we demonstrate an easily accessible electrically driven cavity plasmon in metal-insulator-metal (MIM) tunnel junctions, comprised by a Au nanowire (NW) across two separate ultrasmooth Au electrodes. Two layers of self-assembled thiol molecule defines a reliable tunneling barrier. The contribution from the localized cavity plasmons to the total light emission is found to be dominant over that from the propagating surface plasmon polariton in the MIM waveguide, different from the traditional explanations. This work introduces a simplified method for constructing electrically driven cavity plasmons using crystalline metals, which holds promise for applications in in-situ chemical or biosensing and the development of flexible light-emitting metasurfaces.","PeriodicalId":501827,"journal":{"name":"Nano Express","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141797420","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}
Pub Date : 2024-07-24DOI: 10.1088/2632-959x/ad58fd
Priyanka R Sumbe, Ujjwala Chhote, Gopal Sanyal, Brahmananda Chakraborty, Ahmed Sayeed and Mahendra A More
Nanostructures of Ti3C2Tx, one of the members of the MXenes family, have been successfully prepared by chemical etching of Al from Ti3AlC2 (MAX phase) using Hydrofluoric Acid (HF) for various etching durations at room temperature. The phase, morphological, structural, and chemical analysis was performed using XRD, FESEM, TEM, Raman, and x-ray photoelectron spectroscopy. The surface morphology of as-synthesized Ti3C2Tx (MXene) phase is characterized by stacks of layered sheets like structures. Field electron emission (FEE) behaviour was investigated at the base pressure of 1 × 10−8 mbar. The pristine Ti3AlC2 (MAX) and Ti3C2Tx (MXene) nanosheets emitters showed values of turn-on field (defined at current density ∼ 1 μA cm−2) as 4.18 and 1.67 V μm−1, respectively. Furthermore, maximum emission current density of ∼ 825 μA cm−2 was extracted from the MXene nanosheets emitter at an applied field of 3.60 V μm−1, in contrast to ∼71 μA cm−2 drawn at 7.31 V μm−1 from the pristine MAX emitter. The MXene nanosheets emitter exhibited good emission current stabilities at pre-set values ∼ 10 and 100 μA over 3 h duration. Work function values of the MAX and MXene nanosheets emitters were measured using a retarding field analyzer, and found to be 4.4 and 3.6 eV, respectively. Extensive ab-initio simulations have been performed to provide structural and electronic properties, as well as for estimating the work function of Ti3C2 layered material. The estimated electronic density of states revealed its metallic character. The improved FEE performance exhibited by the 2D layered Ti3C2Tx (MXene) nanosheets emitter is attributed to its unique morphology characterized by high aspect ratio, metallic electronic properties and relatively lower work function.
{"title":"Synthesis, physico-chemical characterization, DFT simulation, and field electron behaviour of 2D layered Ti3C2Tx MXene nanosheets","authors":"Priyanka R Sumbe, Ujjwala Chhote, Gopal Sanyal, Brahmananda Chakraborty, Ahmed Sayeed and Mahendra A More","doi":"10.1088/2632-959x/ad58fd","DOIUrl":"https://doi.org/10.1088/2632-959x/ad58fd","url":null,"abstract":"Nanostructures of Ti3C2Tx, one of the members of the MXenes family, have been successfully prepared by chemical etching of Al from Ti3AlC2 (MAX phase) using Hydrofluoric Acid (HF) for various etching durations at room temperature. The phase, morphological, structural, and chemical analysis was performed using XRD, FESEM, TEM, Raman, and x-ray photoelectron spectroscopy. The surface morphology of as-synthesized Ti3C2Tx (MXene) phase is characterized by stacks of layered sheets like structures. Field electron emission (FEE) behaviour was investigated at the base pressure of 1 × 10−8 mbar. The pristine Ti3AlC2 (MAX) and Ti3C2Tx (MXene) nanosheets emitters showed values of turn-on field (defined at current density ∼ 1 μA cm−2) as 4.18 and 1.67 V μm−1, respectively. Furthermore, maximum emission current density of ∼ 825 μA cm−2 was extracted from the MXene nanosheets emitter at an applied field of 3.60 V μm−1, in contrast to ∼71 μA cm−2 drawn at 7.31 V μm−1 from the pristine MAX emitter. The MXene nanosheets emitter exhibited good emission current stabilities at pre-set values ∼ 10 and 100 μA over 3 h duration. Work function values of the MAX and MXene nanosheets emitters were measured using a retarding field analyzer, and found to be 4.4 and 3.6 eV, respectively. Extensive ab-initio simulations have been performed to provide structural and electronic properties, as well as for estimating the work function of Ti3C2 layered material. The estimated electronic density of states revealed its metallic character. The improved FEE performance exhibited by the 2D layered Ti3C2Tx (MXene) nanosheets emitter is attributed to its unique morphology characterized by high aspect ratio, metallic electronic properties and relatively lower work function.","PeriodicalId":501827,"journal":{"name":"Nano Express","volume":"95 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141785766","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}
Pub Date : 2024-07-23DOI: 10.1088/2632-959x/ad668e
Shermin Adline, Prashant Bhat, D. Kekuda
Tin oxide (SnOx) thin films at varying oxygen flow rates and Nickel oxide (NiO) thin films were deposited by reactive dc magnetron sputtering on glass substrates. Structural, chemical, morphological, optical and electrical properties of the deposited films were studied. XRD studies confirmed that the deposited films were polycrystalline in nature. SnOx thin films have shown two phases such as SnO and SnO2. AFM and SEM were used to analyse the morphology of the films and EDS confirmed the presence of Sn and Ni in the respective films. The examination of the X-ray photoelectron spectrum showed that the sputtered SnOx films contain both Sn2+ and Sn4+ oxidation states and NiO films contain Ni+2 and Ni+3 oxidation states. Photoluminescence study shows strong violet and weak red emission peaks for SnOx films and NiO showed strong emission peaks in the orange-red region. The optical results demonstrate that the films were transparent. The bandgap of SnOx and NiO samples were ~ 3.3 eV and- 3.42 eV, respectively. Further we constructed a p-NiO/n-SnO2 heterojunction diode and its electrical characteristics were thoroughly assessed. Using dark current-voltage measurements, electrical characteristics such saturation current, ideality factor and barrier height were determined. The increase in oxygen flow rate led to reduction in the rectification of the devices. Our findings support the creation of high-performance metal oxide heterojunction for optoelectronic devices.
{"title":"Investigation of diodic behavior in p-NiO/n-SnO2 bilayer heterojunctions fabricated via DC magnetron reactive sputtering","authors":"Shermin Adline, Prashant Bhat, D. Kekuda","doi":"10.1088/2632-959x/ad668e","DOIUrl":"https://doi.org/10.1088/2632-959x/ad668e","url":null,"abstract":"\u0000 Tin oxide (SnOx) thin films at varying oxygen flow rates and Nickel oxide (NiO) thin films were deposited by reactive dc magnetron sputtering on glass substrates. Structural, chemical, morphological, optical and electrical properties of the deposited films were studied. XRD studies confirmed that the deposited films were polycrystalline in nature. SnOx thin films have shown two phases such as SnO and SnO2. AFM and SEM were used to analyse the morphology of the films and EDS confirmed the presence of Sn and Ni in the respective films. The examination of the X-ray photoelectron spectrum showed that the sputtered SnOx films contain both Sn2+ and Sn4+ oxidation states and NiO films contain Ni+2 and Ni+3 oxidation states. Photoluminescence study shows strong violet and weak red emission peaks for SnOx films and NiO showed strong emission peaks in the orange-red region. The optical results demonstrate that the films were transparent. The bandgap of SnOx and NiO samples were ~ 3.3 eV and- 3.42 eV, respectively. Further we constructed a p-NiO/n-SnO2 heterojunction diode and its electrical characteristics were thoroughly assessed. Using dark current-voltage measurements, electrical characteristics such saturation current, ideality factor and barrier height were determined. The increase in oxygen flow rate led to reduction in the rectification of the devices. Our findings support the creation of high-performance metal oxide heterojunction for optoelectronic devices.","PeriodicalId":501827,"journal":{"name":"Nano Express","volume":"136 49","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141811048","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}
Pub Date : 2024-07-18DOI: 10.1088/2632-959x/ad64f0
Vandana Molahalli, Gowri Soman, V. Bhat, Jyothi M S, Uraiwan Sirimahachai, Sanjeev P Maradur, Paola De Padova, N. Chattham, G. Hegde
Biomass-based carbonaceous materials derived from Musa Sapientum have gained much attention in recent years for their application in energy storage devices, especially supercapacitors. In the present work, we synthesized carbonaceous material from banana peel as the biomass precursor by using a pyrolysis method carried out at various temperatures (600, 800, and 1000oC). The characterization of the prepared carbonaceous materials BP600, BP800 and BP1000 was done by using different characterization techniques such as FTIR, XRD, FE-SEM, and TEM, studies. The electrochemical study of the synthesized material was carried out by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) electrochemical impedance spectroscopy (EIS). The supercapacitive performance of the material was studied using a 3-electrode system with 3M KOH as an electrolyte. As a result, the BP600 exhibited a better specific capacitance with higher energy and power densities along with a maximum cyclic stability of 16,000 cycles. To show the practical applicability of the material BP 600, two electrode system studies were carried out as well, which showed preferentially good values for specific capacitance with appreciable power and energy density values. The study provides us with a green approach for the fabrication of non-toxic, low-cost, and environmentally friendly potential porous carbonaceous electrode materials by converting bio-waste into a clean and renewable source of energy.
{"title":"Renewable Musa Sapientum derived porous nano spheres for efficient energy storage devices","authors":"Vandana Molahalli, Gowri Soman, V. Bhat, Jyothi M S, Uraiwan Sirimahachai, Sanjeev P Maradur, Paola De Padova, N. Chattham, G. Hegde","doi":"10.1088/2632-959x/ad64f0","DOIUrl":"https://doi.org/10.1088/2632-959x/ad64f0","url":null,"abstract":"\u0000 Biomass-based carbonaceous materials derived from Musa Sapientum have gained much attention in recent years for their application in energy storage devices, especially supercapacitors. In the present work, we synthesized carbonaceous material from banana peel as the biomass precursor by using a pyrolysis method carried out at various temperatures (600, 800, and 1000oC). The characterization of the prepared carbonaceous materials BP600, BP800 and BP1000 was done by using different characterization techniques such as FTIR, XRD, FE-SEM, and TEM, studies. The electrochemical study of the synthesized material was carried out by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) electrochemical impedance spectroscopy (EIS). The supercapacitive performance of the material was studied using a 3-electrode system with 3M KOH as an electrolyte. As a result, the BP600 exhibited a better specific capacitance with higher energy and power densities along with a maximum cyclic stability of 16,000 cycles. To show the practical applicability of the material BP 600, two electrode system studies were carried out as well, which showed preferentially good values for specific capacitance with appreciable power and energy density values. The study provides us with a green approach for the fabrication of non-toxic, low-cost, and environmentally friendly potential porous carbonaceous electrode materials by converting bio-waste into a clean and renewable source of energy.","PeriodicalId":501827,"journal":{"name":"Nano Express","volume":" 38","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141824323","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}
Nitrogen-containing heterocyclic compounds are currently used for a number of pharmaceutical and agricultural applications because they have biological activities such as antimicrobial, antiviral, antituberculosis, anticancer, analgesic, antioxidant, anti-inflammatory and antidepressant. 1,2,3,4-Tetrazines and 1,2,3-triazoles are examples of high-nitrogen heterocyclic compounds. Coumarins, on the other hand, are lactones that form a group of oxygenated heterocyclic compounds found in plants. In this article, two analogs of 1,2,3,4-tetrazine, two analogs of 1,2,3-triazole and five analogs of coumarin were designed and synthesized. Their chemical structures were characterized by detecting their FTIR, 1H-NMR, and 13C-NMR (APT) spectra. The antioxidant activities of all synthesized molecules were compared at a fixed concentration (0.25 mg/mL) using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method. Molecules 9c and 9e, which showed the highest antioxidant activity, were loaded into PLGA (poly(lactic-co-glycolic) acid) nanoparticles using the oil in water (o/w) single emulsion solvent evaporation method as a model study. Synthesized nanoparticles characterized for particle size, zeta potential, functional groups, morphology, and release properties. Particle size and zeta potential of 9c/NP were determined as 216.1±8.944 nm and -14.1±2.40 mV, respectively. The particle size and zeta potential for 9e/NP were measured as 222.0±12.490 nm and -12.4±1.42 mV respectively. The study results obtained on model nanoparticle systems with elucidated physicochemical properties may have the potential to provide a promising basis for oxidative stress-related diseases in the future.
{"title":"Design, synthesis and anti-oxidant activities of novel 1,2,3,4-tetrazine, 1,2,3-triazoles and coumarin derivatives and their nanoparticular encapsulation","authors":"Oznur Eyilcim, Burcu Belmen, Irem Coksu, Serap Acar, C. Yolacan, Omer Tahir Gunkara","doi":"10.1088/2632-959x/ad64f1","DOIUrl":"https://doi.org/10.1088/2632-959x/ad64f1","url":null,"abstract":"\u0000 Nitrogen-containing heterocyclic compounds are currently used for a number of pharmaceutical and agricultural applications because they have biological activities such as antimicrobial, antiviral, antituberculosis, anticancer, analgesic, antioxidant, anti-inflammatory and antidepressant. 1,2,3,4-Tetrazines and 1,2,3-triazoles are examples of high-nitrogen heterocyclic compounds. Coumarins, on the other hand, are lactones that form a group of oxygenated heterocyclic compounds found in plants. In this article, two analogs of 1,2,3,4-tetrazine, two analogs of 1,2,3-triazole and five analogs of coumarin were designed and synthesized. Their chemical structures were characterized by detecting their FTIR, 1H-NMR, and 13C-NMR (APT) spectra. The antioxidant activities of all synthesized molecules were compared at a fixed concentration (0.25 mg/mL) using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method. Molecules 9c and 9e, which showed the highest antioxidant activity, were loaded into PLGA (poly(lactic-co-glycolic) acid) nanoparticles using the oil in water (o/w) single emulsion solvent evaporation method as a model study. Synthesized nanoparticles characterized for particle size, zeta potential, functional groups, morphology, and release properties. Particle size and zeta potential of 9c/NP were determined as 216.1±8.944 nm and -14.1±2.40 mV, respectively. The particle size and zeta potential for 9e/NP were measured as 222.0±12.490 nm and -12.4±1.42 mV respectively. The study results obtained on model nanoparticle systems with elucidated physicochemical properties may have the potential to provide a promising basis for oxidative stress-related diseases in the future.","PeriodicalId":501827,"journal":{"name":"Nano Express","volume":" 48","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141825475","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}
Pub Date : 2024-07-09DOI: 10.1088/2632-959x/ad5d81
Anupam Ghosh, Riya Wadhwa, Shivani, Sonia Deswal, Pradeep Kumar and Mukesh Kumar
The low responsivity of conventional Silicon photodiodes in ultraviolet and near-infrared regimes restricts their utility as broadband photodetectors (BBPDs). Despite ongoing investigations into various p-n heterostructures for Silicon-based BBPDs, challenges such as high dark current (Idark), low collection efficiency, low detectivity, and compatibility issues with large-scale Silicon-based devices persist. In this context, we have fabricated relatively unexplored n-Er2O3/p-Si heterojunction-based BBPDs. Polycrystalline Er2O3 thin films (∼110 nm) were deposited on p-Si 〈100〉 substrates by radio frequency magnetron sputtering. Although this process induces a microstrain of approximately 0.022 and a dislocation density of about 0.00303/nm2, the presence of optically active defects is minimal, indicated by a low Urbach energy (∼0.35 eV). X-ray photoelectron spectroscopy (XPS) analysis confirms staggered band alignment at the heterointerface, facilitating efficient charge carrier separation and transport. Consequently, the In/p-Si/n-Er2O3/In device demonstrated significant BBPD properties– low Idark ∼0.15 μA (at +5 V), photo-to-dark current ratio (PDCR) ∼6.5 (at +5 V, 700 nm) with a maximum photoresponsivity ∼22.3 A W−1, and impressive detectivity (∼1013 Jones) even in UV-C region where traditional silicon-based photodetectors respond feebly. The device also demonstrates transient photo-response across an ultrawide spectrum (254 nm–1200 nm) with a fast rise time/fall time ∼79 ms/∼86 ms (at −5 V for 600 nm illumination). This work establishes a straightforward and reliable method for proper material engineering, surface texturing, staggered heterojunction formation, and high-performance BBPD fabrication with prominent broad-spectrum responsivity, sizeable detectivity, and fast response. The integration of these BBPDs with Silicon opens possibilities for their use in electronic devices containing optical switches for communications and broadband image sensors, enhancing their utility in various applications.
{"title":"Staggered band alignment of n-Er2O3/p-Si heterostructure for the fabrication of a high-performance broadband photodetector","authors":"Anupam Ghosh, Riya Wadhwa, Shivani, Sonia Deswal, Pradeep Kumar and Mukesh Kumar","doi":"10.1088/2632-959x/ad5d81","DOIUrl":"https://doi.org/10.1088/2632-959x/ad5d81","url":null,"abstract":"The low responsivity of conventional Silicon photodiodes in ultraviolet and near-infrared regimes restricts their utility as broadband photodetectors (BBPDs). Despite ongoing investigations into various p-n heterostructures for Silicon-based BBPDs, challenges such as high dark current (Idark), low collection efficiency, low detectivity, and compatibility issues with large-scale Silicon-based devices persist. In this context, we have fabricated relatively unexplored n-Er2O3/p-Si heterojunction-based BBPDs. Polycrystalline Er2O3 thin films (∼110 nm) were deposited on p-Si 〈100〉 substrates by radio frequency magnetron sputtering. Although this process induces a microstrain of approximately 0.022 and a dislocation density of about 0.00303/nm2, the presence of optically active defects is minimal, indicated by a low Urbach energy (∼0.35 eV). X-ray photoelectron spectroscopy (XPS) analysis confirms staggered band alignment at the heterointerface, facilitating efficient charge carrier separation and transport. Consequently, the In/p-Si/n-Er2O3/In device demonstrated significant BBPD properties– low Idark ∼0.15 μA (at +5 V), photo-to-dark current ratio (PDCR) ∼6.5 (at +5 V, 700 nm) with a maximum photoresponsivity ∼22.3 A W−1, and impressive detectivity (∼1013 Jones) even in UV-C region where traditional silicon-based photodetectors respond feebly. The device also demonstrates transient photo-response across an ultrawide spectrum (254 nm–1200 nm) with a fast rise time/fall time ∼79 ms/∼86 ms (at −5 V for 600 nm illumination). This work establishes a straightforward and reliable method for proper material engineering, surface texturing, staggered heterojunction formation, and high-performance BBPD fabrication with prominent broad-spectrum responsivity, sizeable detectivity, and fast response. The integration of these BBPDs with Silicon opens possibilities for their use in electronic devices containing optical switches for communications and broadband image sensors, enhancing their utility in various applications.","PeriodicalId":501827,"journal":{"name":"Nano Express","volume":"34 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141585343","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}
In this work, zinc oxide (ZnO) ceramics were synthesized containing 0-5wt% of cubic yttrium sesquioxide (Y2O3) nanoparticles with solid state sintering technique at 1150°C. The secondary phase of Y2O3 did not enter into the crystalline zinc oxide. The Y2O3 acts as an inhibitor of grain growth. The absorption of the free charge carriers by the Y2O3 phase influences the infrared transmissions. The minimization of the phase mismatch while transferring the electric signal caused lower losses when Y2O3 was added to the zinc oxide matrices. The presence of the cubic sesquioxide at the grain boundary contributes to the interfacial polarization at lower frequencies when an alternating field is applied to the ceramics. These properties are anticipated to show a wider range of physical, optical and dielectric properties of ZnO: Y ceramics for optoelectronic applications.
{"title":"Investigation of the role of yttrium sesquioxide nanoparticles on the properties of zinc oxide ceramics","authors":"Mônica Pereira Soares, Girija Atrey, Prasun Banerjee and Adolfo Franco Junior","doi":"10.1088/2632-959x/ad5d82","DOIUrl":"https://doi.org/10.1088/2632-959x/ad5d82","url":null,"abstract":"In this work, zinc oxide (ZnO) ceramics were synthesized containing 0-5wt% of cubic yttrium sesquioxide (Y2O3) nanoparticles with solid state sintering technique at 1150°C. The secondary phase of Y2O3 did not enter into the crystalline zinc oxide. The Y2O3 acts as an inhibitor of grain growth. The absorption of the free charge carriers by the Y2O3 phase influences the infrared transmissions. The minimization of the phase mismatch while transferring the electric signal caused lower losses when Y2O3 was added to the zinc oxide matrices. The presence of the cubic sesquioxide at the grain boundary contributes to the interfacial polarization at lower frequencies when an alternating field is applied to the ceramics. These properties are anticipated to show a wider range of physical, optical and dielectric properties of ZnO: Y ceramics for optoelectronic applications.","PeriodicalId":501827,"journal":{"name":"Nano Express","volume":"53 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141585344","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}
Pub Date : 2024-07-09DOI: 10.1088/2632-959x/ad5d80
Jerry O Adeyemi, Timothy O Ajiboye, Adebola O Oyedeji, Moganavelli Singh and Olaniyi A Fawole
Although hematite (Fe2O3) nanoparticles are gaining attention for biomedical purposes due to their unique properties, eco-friendly synthesis using plant extracts is being explored due to toxicity concerns of the resulting material. This study explores the use of plant extracts (Dovyalis caffra leaf extracts) for the synthesis of Fe2O3 nanoparticles alongside their cytotoxicity profile using human embryonic kidney cells (HEK293) and human cervical cancer cells (HeLa). The physicochemical properties of the prepared nanoparticles were established using x-ray diffraction (XRD) and microscopy techniques, confirming their crystalline nature and spherical morphology with minimal agglomeration. Using the MTT assay approach, the cytotoxicity profile of the nanoparticles revealed dose-dependent cytotoxic effects, with higher specificity towards cancer cells and very low toxicity towards the human cell line, suggesting safe usage as biomedical agents. While the standard drug 5-Fluorouracil possessed significantly higher cytotoxicity, its unwanted high toxicity towards normal human cells makes the Fe2O3 nanoparticles a better choice. These findings suggest the potential of Dovyalis caffra leaf extract-mediated Fe2O3 nanoparticles for biomedical applications, emphasizing their low toxicity towards normal human cells and specificity towards cancer cells.
{"title":"Cytotoxic evaluation of Dovyalis Caffra leaf extract-mediated hematite-(Fe2O3) nanoparticles for biological applications","authors":"Jerry O Adeyemi, Timothy O Ajiboye, Adebola O Oyedeji, Moganavelli Singh and Olaniyi A Fawole","doi":"10.1088/2632-959x/ad5d80","DOIUrl":"https://doi.org/10.1088/2632-959x/ad5d80","url":null,"abstract":"Although hematite (Fe2O3) nanoparticles are gaining attention for biomedical purposes due to their unique properties, eco-friendly synthesis using plant extracts is being explored due to toxicity concerns of the resulting material. This study explores the use of plant extracts (Dovyalis caffra leaf extracts) for the synthesis of Fe2O3 nanoparticles alongside their cytotoxicity profile using human embryonic kidney cells (HEK293) and human cervical cancer cells (HeLa). The physicochemical properties of the prepared nanoparticles were established using x-ray diffraction (XRD) and microscopy techniques, confirming their crystalline nature and spherical morphology with minimal agglomeration. Using the MTT assay approach, the cytotoxicity profile of the nanoparticles revealed dose-dependent cytotoxic effects, with higher specificity towards cancer cells and very low toxicity towards the human cell line, suggesting safe usage as biomedical agents. While the standard drug 5-Fluorouracil possessed significantly higher cytotoxicity, its unwanted high toxicity towards normal human cells makes the Fe2O3 nanoparticles a better choice. These findings suggest the potential of Dovyalis caffra leaf extract-mediated Fe2O3 nanoparticles for biomedical applications, emphasizing their low toxicity towards normal human cells and specificity towards cancer cells.","PeriodicalId":501827,"journal":{"name":"Nano Express","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141585341","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}
Pub Date : 2024-07-04DOI: 10.1088/2632-959x/ad5b7a
Ritu Raj, Imtiaz Ahmed, Vikash Kumar, Gajendra Prasad Singh and Krishna Kanta Haldar
The fabrication of nanostructured protein-inorganic hybrid materials is crucial for the development of advanced multifunctional materials. Protein-inorganic mesoporous composites are gaining attention due to their remarkable properties, including large surface areas and active surface functional groups. We have successfully synthesized mesoporous BSA/Zn3(PO4)2/Cr2O3 catalysts to improve the kinetics of the oxygen evolution reaction (OER) in electrocatalytic water splitting for sustainable energy generation. This approach utilizes BSA in the synthesis process and is environmentally friendly. By adjusting the BSA quantity, we could control the yield of BSA/Zn3(PO4)2/Cr2O3 mesoporous. We employed various techniques, including FE-SEM, XRD, and FTIR, to analyze the morphology and structural characteristics of the biogenic BSA/Zn3(PO4)2/Cr2O3 electrocatalyst. Our comprehensive evaluation of the electrocatalytic OER activity of the BSA/Zn3(PO4)2/Cr2O3 hybrid structure demonstrated its remarkable performance. The biologically synthesized catalyst exhibited exceptional OER efficiency, maintaining a high current density of 10 mA cm−2 at very low overpotentials (only 216 mV) under alkaline conditions. The elongated peptide backbone of BSA significantly facilitated ion and electron transport, contributing to improved OER activity. The synergistic interaction between various amino acids from BSA and the metal ions within Zn3(PO4)2/Cr2O3 can be attributed to this enhancement, highlighting the potential of this hybrid structure in electrocatalytic OER applications.
制备纳米结构的蛋白质-无机杂化材料对于开发先进的多功能材料至关重要。蛋白质-无机介孔复合材料因其大比表面积和表面活性官能团等显著特性而备受关注。我们成功合成了介孔 BSA/Zn3(PO4)2/Cr2O3 催化剂，以改善电催化水分离过程中氧进化反应（OER）的动力学，从而实现可持续能源生产。这种方法在合成过程中利用了 BSA，并且对环境友好。通过调整 BSA 的用量，我们可以控制 BSA/Zn3(PO4)2/Cr2O3 介孔的产率。我们采用 FE-SEM、XRD 和 FTIR 等多种技术分析了生物源 BSA/Zn3(PO4)2/Cr2O3 电催化剂的形态和结构特征。我们对 BSA/Zn3(PO4)2/Cr2O3杂化结构的电催化 OER 活性进行了全面评估，结果表明其性能显著。这种生物合成的催化剂具有卓越的 OER 效率，在碱性条件下，过电位很低（仅 216 mV），却能保持 10 mA cm-2 的高电流密度。BSA 的拉长肽骨显著促进了离子和电子的传输，有助于提高 OER 活性。BSA 中的各种氨基酸与 Zn3(PO4)2/Cr2O3 中的金属离子之间的协同作用可归因于这种增强作用，凸显了这种杂化结构在电催化 OER 应用中的潜力。
{"title":"Biogenic Bovine Serum Albumin/Zn3(PO4)2/Cr2O3 hybrid electrocatalyst for improved oxygen evolution reaction","authors":"Ritu Raj, Imtiaz Ahmed, Vikash Kumar, Gajendra Prasad Singh and Krishna Kanta Haldar","doi":"10.1088/2632-959x/ad5b7a","DOIUrl":"https://doi.org/10.1088/2632-959x/ad5b7a","url":null,"abstract":"The fabrication of nanostructured protein-inorganic hybrid materials is crucial for the development of advanced multifunctional materials. Protein-inorganic mesoporous composites are gaining attention due to their remarkable properties, including large surface areas and active surface functional groups. We have successfully synthesized mesoporous BSA/Zn3(PO4)2/Cr2O3 catalysts to improve the kinetics of the oxygen evolution reaction (OER) in electrocatalytic water splitting for sustainable energy generation. This approach utilizes BSA in the synthesis process and is environmentally friendly. By adjusting the BSA quantity, we could control the yield of BSA/Zn3(PO4)2/Cr2O3 mesoporous. We employed various techniques, including FE-SEM, XRD, and FTIR, to analyze the morphology and structural characteristics of the biogenic BSA/Zn3(PO4)2/Cr2O3 electrocatalyst. Our comprehensive evaluation of the electrocatalytic OER activity of the BSA/Zn3(PO4)2/Cr2O3 hybrid structure demonstrated its remarkable performance. The biologically synthesized catalyst exhibited exceptional OER efficiency, maintaining a high current density of 10 mA cm−2 at very low overpotentials (only 216 mV) under alkaline conditions. The elongated peptide backbone of BSA significantly facilitated ion and electron transport, contributing to improved OER activity. The synergistic interaction between various amino acids from BSA and the metal ions within Zn3(PO4)2/Cr2O3 can be attributed to this enhancement, highlighting the potential of this hybrid structure in electrocatalytic OER applications.","PeriodicalId":501827,"journal":{"name":"Nano Express","volume":"68 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141552513","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}
Colloidal semiconductor nanocrystals (NCs) or quantum dots (QDs) have shown great potential for solution-processable photodetector due to their exceptional optical and electronic properties. However, broadband and sensitive photodetection from single QDs- based devices is quite challenging. Nano-heterojunction with proper band alignment based on two different materials offers significant advantages for developing broadband photodetector. Herein, we report ultraviolet–visible (UV–Vis) to near-infrared (NIR) light-responsive photodetector based on solution-processed nano-heterojunction of visible light absorber CsPbBr3 perovskite NCs and wide absorption range, environment-friendly Bi2S3 QDs. Our results demonstrate that the CsPbBr3–Bi2S3 nano-heterojunction-based photodetector has higher responsivity (380 μA/W at a wavelength of 532 nm) and higher specific detectivity (1.02 × 105 Jones), as compared to the individual CsPbBr3 or Bi2S3 QDs based devices. Interestingly, the detection wavelength range of our heterojunction device is further extended to the near-infrared region (1064 nm) due to the broadband absorption range of Bi2S3 QDs, which is not observed in the visible light absorber CsPbBr3 devices. Remarkably, the responsivity of the heterojunction device is 90 μA W−1. The enhanced specific detectivity and the broadband response of hybrid devices are attributed to the improved charge carrier generation, efficient charge separation and transfer at the interface between CsPbBr3 and Bi2S3 QDs.
{"title":"Bismuth sulfide quantum dots-CsPbBr3 perovskite nanocrystals heterojunction for enhanced broadband photodetection","authors":"Lalita, Aditya Yadav, Harshit Sharma, Govind Gupta, Razi Ahmad, Vidya Nand Singh and Ritu Srivastava","doi":"10.1088/2632-959x/ad52b2","DOIUrl":"https://doi.org/10.1088/2632-959x/ad52b2","url":null,"abstract":"Colloidal semiconductor nanocrystals (NCs) or quantum dots (QDs) have shown great potential for solution-processable photodetector due to their exceptional optical and electronic properties. However, broadband and sensitive photodetection from single QDs- based devices is quite challenging. Nano-heterojunction with proper band alignment based on two different materials offers significant advantages for developing broadband photodetector. Herein, we report ultraviolet–visible (UV–Vis) to near-infrared (NIR) light-responsive photodetector based on solution-processed nano-heterojunction of visible light absorber CsPbBr3 perovskite NCs and wide absorption range, environment-friendly Bi2S3 QDs. Our results demonstrate that the CsPbBr3–Bi2S3 nano-heterojunction-based photodetector has higher responsivity (380 μA/W at a wavelength of 532 nm) and higher specific detectivity (1.02 × 105 Jones), as compared to the individual CsPbBr3 or Bi2S3 QDs based devices. Interestingly, the detection wavelength range of our heterojunction device is further extended to the near-infrared region (1064 nm) due to the broadband absorption range of Bi2S3 QDs, which is not observed in the visible light absorber CsPbBr3 devices. Remarkably, the responsivity of the heterojunction device is 90 μA W−1. The enhanced specific detectivity and the broadband response of hybrid devices are attributed to the improved charge carrier generation, efficient charge separation and transfer at the interface between CsPbBr3 and Bi2S3 QDs.","PeriodicalId":501827,"journal":{"name":"Nano Express","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141504643","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}
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