S. Inoue, Hiroki Tanioka, Takeshi Yasui, Y. Morimoto, M. Kawasaki, M. Kawasaki, T. Minamikawa
Raman spectroscopy is a technique that can visualize various molecular information noninvasively without the need for invasive pretreatment of samples such as staining. However, Raman scattering light is very weak, and thus Raman spectroscopy has limitations in terms of molecular sensitivity and measurement time. One solution to overcome the problem of weak signal intensity is optical enhancement based on the plasmon resonance effect. Surface-enhanced Raman scattering (SERS) spectroscopy enables highly sensitive Raman spectroscopy owing to the enhancing near-field produced by plasmon resonance. This enhancing field is formed in an area of about 10 nm around the metallic nanostructures. However, the direct contact between the metallic nanostructures and the analyte molecules causes denaturation of the metallic nanostructures and the analyte molecules themselves, limiting the Raman spectroscopic analysis and its applications. In the present study, we developed a remote plasmonic enhancement (RPE) method, which is expected to provide a high enhancement by plasmon-molecule remote coupling via a silica columnar structure of several tens nm in size to a metallic nanostructure. We demonstrated that the RPE could be applied to Raman spectroscopy (RPERS, remote plasmonic-enhanced Raman spectroscopy). We have confirmed the high enhancement of more than 104 by RPERS and clarified the fundamental characteristics of the RPERS.
{"title":"Fundamental characteristics of remote plasmonic-enhanced Raman spectroscopy without close contact between analyte and metallic nanostructure","authors":"S. Inoue, Hiroki Tanioka, Takeshi Yasui, Y. Morimoto, M. Kawasaki, M. Kawasaki, T. Minamikawa","doi":"10.1117/12.2675799","DOIUrl":"https://doi.org/10.1117/12.2675799","url":null,"abstract":"Raman spectroscopy is a technique that can visualize various molecular information noninvasively without the need for invasive pretreatment of samples such as staining. However, Raman scattering light is very weak, and thus Raman spectroscopy has limitations in terms of molecular sensitivity and measurement time. One solution to overcome the problem of weak signal intensity is optical enhancement based on the plasmon resonance effect. Surface-enhanced Raman scattering (SERS) spectroscopy enables highly sensitive Raman spectroscopy owing to the enhancing near-field produced by plasmon resonance. This enhancing field is formed in an area of about 10 nm around the metallic nanostructures. However, the direct contact between the metallic nanostructures and the analyte molecules causes denaturation of the metallic nanostructures and the analyte molecules themselves, limiting the Raman spectroscopic analysis and its applications. In the present study, we developed a remote plasmonic enhancement (RPE) method, which is expected to provide a high enhancement by plasmon-molecule remote coupling via a silica columnar structure of several tens nm in size to a metallic nanostructure. We demonstrated that the RPE could be applied to Raman spectroscopy (RPERS, remote plasmonic-enhanced Raman spectroscopy). We have confirmed the high enhancement of more than 104 by RPERS and clarified the fundamental characteristics of the RPERS.","PeriodicalId":13820,"journal":{"name":"International Conference on Nanoscience, Engineering and Technology (ICONSET 2011)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74616058","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}
Yaobin Dong, Zih-Chun Su, Bo Chen, Yi-Long Chen, Du-Ting Cheng, Kun-Rong Lin, Ching-Fuh Lin
Localized surface plasmon resonance (LSPR) from metal nanoparticles (NPs) has been widely applied to enhance the performance of photodetectors and has been studied by many groups. Due to the limitation of the bandgap, silicon-based (Si-based) devices encounter challenges in sensing infrared region. To overcome this issue, this study discusses how the silver (Ag) NPs to modify Si-based Schottky photodetectors and enhance mid-infrared (MIR) responsivity via rapid thermal annealing (RTA) process by inducing LSPR when illuminating. Under an incident light source at 3460 nm wavelength, the responsivity of the device annealing at 175°C is increased from 0.4481 mA/W to 0.6872 mA/W, which is enhanced 1.533 times compared to device without annealing. In addition, using COMSOL software for electric field intensity simulation confirms that Ag NPs can indeed enhance the electric field intensity to increase the induced LSPR. Therefore, it is demonstrated that the response signal of MIR can be enhanced and amplified by Ag NPs in Schottky devices under the same measurement conditions, achieving the ability to detect MIR region in Si-based Schottky devices.
{"title":"Improvement by localized surface plasmon resonance enhancement from Ag nanoparticles in Si-based photodetector","authors":"Yaobin Dong, Zih-Chun Su, Bo Chen, Yi-Long Chen, Du-Ting Cheng, Kun-Rong Lin, Ching-Fuh Lin","doi":"10.1117/12.2676312","DOIUrl":"https://doi.org/10.1117/12.2676312","url":null,"abstract":"Localized surface plasmon resonance (LSPR) from metal nanoparticles (NPs) has been widely applied to enhance the performance of photodetectors and has been studied by many groups. Due to the limitation of the bandgap, silicon-based (Si-based) devices encounter challenges in sensing infrared region. To overcome this issue, this study discusses how the silver (Ag) NPs to modify Si-based Schottky photodetectors and enhance mid-infrared (MIR) responsivity via rapid thermal annealing (RTA) process by inducing LSPR when illuminating. Under an incident light source at 3460 nm wavelength, the responsivity of the device annealing at 175°C is increased from 0.4481 mA/W to 0.6872 mA/W, which is enhanced 1.533 times compared to device without annealing. In addition, using COMSOL software for electric field intensity simulation confirms that Ag NPs can indeed enhance the electric field intensity to increase the induced LSPR. Therefore, it is demonstrated that the response signal of MIR can be enhanced and amplified by Ag NPs in Schottky devices under the same measurement conditions, achieving the ability to detect MIR region in Si-based Schottky devices.","PeriodicalId":13820,"journal":{"name":"International Conference on Nanoscience, Engineering and Technology (ICONSET 2011)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86162020","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}
Sara Abbasi, Bastián Carnero Groba, I. Weets, Qing Liu, F. Ferranti, H. Ottevaere
Hemoglobinopathies are the most common genetic disorders caused by a mutation in the genes encoding for one of the globin chains and leading to structural (hemoglobin [Hb] variants) or quantitative defects (thalassemias) in hemoglobin. Early diagnosis and characterization of hemoglobinopathies are essential to avoid severe hematological consequences in the offspring of healthy carriers of a mutation. Despite being extensively studied, hemoglobinopathies continue to provide a diagnostic challenge. Sickle-cell hemoglobin (HbS) is the most common and clinically significant hemoglobin variant among all Hb variants. To overcome the challenge of diagnosing Hb variants, we propose the use of Surface-Enhanced Raman Spectroscopy (SERS). SERS is a powerful label-free tool for providing fingerprint structural information of analyses. It can rapidly generate the spectral signature of samples. This study investigates the structural differences between HbS and normal Hb using gold nanopillar SERS substrates with a leaning effect. The SERS spectra of Hb variants showed subtle spectral differences between HbS and normal Hb located in the valine (975 cm-1) and glutamic acid (1547 cm-1) band, reflecting the amino acid substitution in the HbS β-globin chain. We also automated the identification of HbS and normal Hb with principal component analysis (PCA) combined with support vector machine (SVM) and linear discriminant analysis (LDA) classifiers, leading to an accuracy of 98% and 96%, respectively. This study demonstrated that SERS can provide a fast, highly sensitive, noninvasive, and accurate detection module for the diagnosis of Sickle-cell disease and potentially other hemoglobinopathies.
{"title":"SERS biosensing of sickle cell hemoglobin from normal hemoglobin","authors":"Sara Abbasi, Bastián Carnero Groba, I. Weets, Qing Liu, F. Ferranti, H. Ottevaere","doi":"10.1117/12.2675806","DOIUrl":"https://doi.org/10.1117/12.2675806","url":null,"abstract":"Hemoglobinopathies are the most common genetic disorders caused by a mutation in the genes encoding for one of the globin chains and leading to structural (hemoglobin [Hb] variants) or quantitative defects (thalassemias) in hemoglobin. Early diagnosis and characterization of hemoglobinopathies are essential to avoid severe hematological consequences in the offspring of healthy carriers of a mutation. Despite being extensively studied, hemoglobinopathies continue to provide a diagnostic challenge. Sickle-cell hemoglobin (HbS) is the most common and clinically significant hemoglobin variant among all Hb variants. To overcome the challenge of diagnosing Hb variants, we propose the use of Surface-Enhanced Raman Spectroscopy (SERS). SERS is a powerful label-free tool for providing fingerprint structural information of analyses. It can rapidly generate the spectral signature of samples. This study investigates the structural differences between HbS and normal Hb using gold nanopillar SERS substrates with a leaning effect. The SERS spectra of Hb variants showed subtle spectral differences between HbS and normal Hb located in the valine (975 cm-1) and glutamic acid (1547 cm-1) band, reflecting the amino acid substitution in the HbS β-globin chain. We also automated the identification of HbS and normal Hb with principal component analysis (PCA) combined with support vector machine (SVM) and linear discriminant analysis (LDA) classifiers, leading to an accuracy of 98% and 96%, respectively. This study demonstrated that SERS can provide a fast, highly sensitive, noninvasive, and accurate detection module for the diagnosis of Sickle-cell disease and potentially other hemoglobinopathies.","PeriodicalId":13820,"journal":{"name":"International Conference on Nanoscience, Engineering and Technology (ICONSET 2011)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91192418","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}
M. Mishra, R. Saha, S. Bhowmick, Subhananda Chakrabarti
Ga2O3 has established to be a promising material for deep UV and UV optoelectronics and sensing applications. However, a major drawback of Ga2O3 thin film based optoelectronic devices is the existence of native point defects which can result in the creation of sub-bandgap absorption, carrier scattering centres, and leakage channels and becomes an obstruction to their efficient device applications. To overcome this high temperature annealing processes are required which not only leads to a rise in the thermal budget but also put many fabrication and technological bounds in device fabrication. Therefore, in this work we report room temperature ultraviolet-ozone (UVO) annealing as a facile and cost-effective method which can control defect states and improve the optical efficiency of Ga2O3 thin film. The Ga2O3 thin films were deposited by radio frequency (RF) sputtering technique on p-Si at room temperature. The grown films were subsequently subjected to UV-Ozone (UVO) annealing for 30, 50, 70, and 90 min at room temperature. The atomic force microscopy result shows the impacts of UV-Ozone (UVO) annealing time on the film roughness which further associated with reduced oxygen vacancies (Vo) concentration. Optimum time of UVO annealing for Ga2O3 thin films was estimated to be 50 min. Finally, the variation in current-voltage (I-V) characteristics of Ga2O3/p-Si heterojunctions are estimated to understand the effect UVO annealing on its electrical properties of RF sputtered Ga2O3 thin film.
{"title":"Impact of UV-ozone (UVO) treatment on optical and electrical properties of RF sputtered Ga2O3 thin films for opto-electronic application","authors":"M. Mishra, R. Saha, S. Bhowmick, Subhananda Chakrabarti","doi":"10.1117/12.2679102","DOIUrl":"https://doi.org/10.1117/12.2679102","url":null,"abstract":"Ga2O3 has established to be a promising material for deep UV and UV optoelectronics and sensing applications. However, a major drawback of Ga2O3 thin film based optoelectronic devices is the existence of native point defects which can result in the creation of sub-bandgap absorption, carrier scattering centres, and leakage channels and becomes an obstruction to their efficient device applications. To overcome this high temperature annealing processes are required which not only leads to a rise in the thermal budget but also put many fabrication and technological bounds in device fabrication. Therefore, in this work we report room temperature ultraviolet-ozone (UVO) annealing as a facile and cost-effective method which can control defect states and improve the optical efficiency of Ga2O3 thin film. The Ga2O3 thin films were deposited by radio frequency (RF) sputtering technique on p-Si at room temperature. The grown films were subsequently subjected to UV-Ozone (UVO) annealing for 30, 50, 70, and 90 min at room temperature. The atomic force microscopy result shows the impacts of UV-Ozone (UVO) annealing time on the film roughness which further associated with reduced oxygen vacancies (Vo) concentration. Optimum time of UVO annealing for Ga2O3 thin films was estimated to be 50 min. Finally, the variation in current-voltage (I-V) characteristics of Ga2O3/p-Si heterojunctions are estimated to understand the effect UVO annealing on its electrical properties of RF sputtered Ga2O3 thin film.","PeriodicalId":13820,"journal":{"name":"International Conference on Nanoscience, Engineering and Technology (ICONSET 2011)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83884047","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}
A. Herrera-Rodríguez, T. López-Luke, G. Ramírez-García, Andrea Ceja-Fdez, Salvador Barrientos, Víctor Hugo Romero Arellano, J. Zárate-Medina
In this research, Yb3+ -Tm3+ co-doped ZrO2 nanoparticles (ZrO2:2Yb3+ -xTm3+; x=0.0125, 0.025, 0.05, 0.1, and 0.2 mol%) were synthesized using ethylenediamine and Pluronic F-127® as precipitating and surfactant agents, respectively, through a sonochemical method assisted by hydrothermal treatment and subsequent annealing as an innovative, simple, and fast route. Structural, morphological, and chemical characterization was determined by XRD, SEM, and FT-IR. The photoluminescent characterization was performed using a spectrometer with an excitation wavelength of 975 nm. The SEM technique confirms the formation of spherical and semispherical nanoparticles dispersed of sizes less than 110 nm. Furthermore, XRD results proved that the solids have monoclinic and tetragonal crystalline structure for undoped ZrO2 and the tetragonal phase was stabilized with Yb3+ -Tm3+ co-doped ZrO2. At the same time, FT-IR spectroscopy showed the functional groups corresponding to –OH residual, C-H, and C=C bonds due to surfactant agent remand and metallic oxide bonding of Zr-O, corresponding to the tetragonal crystal structure, principally. On the other hand, photoluminescent characterization exhibited upconversion (UC) emissions at 488, 656, and 800 nm due to 1G4→3H6, 1G4→3F4, and 3H4→3H6 transitions of Tm3+, respectively. These emissions increase in intensity due to the increment of Tm3+ concentration until 0.1mol%; lower and higher to this concentration, the photoluminescent intensity decrease. ZrO2:2Yb3+ -0.1Tm3+ nanoparticles showed the highest enhancement (144%) at 800 nm concerning the ZrO2:2Yb3+ -0.0125Tm3+ sample.
{"title":"Enhancement of NIR emission varying thulium of ZrO2:2Yb3+-xTm3+ nanoparticles by sonochemical method","authors":"A. Herrera-Rodríguez, T. López-Luke, G. Ramírez-García, Andrea Ceja-Fdez, Salvador Barrientos, Víctor Hugo Romero Arellano, J. Zárate-Medina","doi":"10.1117/12.2677059","DOIUrl":"https://doi.org/10.1117/12.2677059","url":null,"abstract":"In this research, Yb3+ -Tm3+ co-doped ZrO2 nanoparticles (ZrO2:2Yb3+ -xTm3+; x=0.0125, 0.025, 0.05, 0.1, and 0.2 mol%) were synthesized using ethylenediamine and Pluronic F-127® as precipitating and surfactant agents, respectively, through a sonochemical method assisted by hydrothermal treatment and subsequent annealing as an innovative, simple, and fast route. Structural, morphological, and chemical characterization was determined by XRD, SEM, and FT-IR. The photoluminescent characterization was performed using a spectrometer with an excitation wavelength of 975 nm. The SEM technique confirms the formation of spherical and semispherical nanoparticles dispersed of sizes less than 110 nm. Furthermore, XRD results proved that the solids have monoclinic and tetragonal crystalline structure for undoped ZrO2 and the tetragonal phase was stabilized with Yb3+ -Tm3+ co-doped ZrO2. At the same time, FT-IR spectroscopy showed the functional groups corresponding to –OH residual, C-H, and C=C bonds due to surfactant agent remand and metallic oxide bonding of Zr-O, corresponding to the tetragonal crystal structure, principally. On the other hand, photoluminescent characterization exhibited upconversion (UC) emissions at 488, 656, and 800 nm due to 1G4→3H6, 1G4→3F4, and 3H4→3H6 transitions of Tm3+, respectively. These emissions increase in intensity due to the increment of Tm3+ concentration until 0.1mol%; lower and higher to this concentration, the photoluminescent intensity decrease. ZrO2:2Yb3+ -0.1Tm3+ nanoparticles showed the highest enhancement (144%) at 800 nm concerning the ZrO2:2Yb3+ -0.0125Tm3+ sample.","PeriodicalId":13820,"journal":{"name":"International Conference on Nanoscience, Engineering and Technology (ICONSET 2011)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89179755","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}
Shea Sanvordenker, Jungchul Noh, Jamie Howell, R. Pimpinella, B. Korgel
Mercury telluride (HgTe) nanocrystal quantum dot-based infrared photodetectors provide a low-cost alternative to mercury cadmium telluride (MCT) bulk alloy devices made through epitaxial growth methods. The size-tunable optical properties of HgTe colloidal quantum dots (CQDs) make it possible to synthetically target a range of absorption edge wavelengths encompassing the infrared region. In this work, we report the synthesis of HgTe CQDs with high aspect ratios using solution-based colloidal techniques. The radial diameter of the arms of tripodal HgTe CQDs can be adjusted between 3 and 7 nm, with corresponding decreases in aspect ratios (arm length/radial diameter) from six to two, respectively. Tripodal HgTe CQDs exhibit room temperature photoconductivity with optical response ranging from the short wavelength infrared (SWIR) to mid-wavelength infrared (MWIR) spectral region, with optical cutoffs increasing from 1.7 to 3.5 µm with increasing CQD arm diameter. These tripodal HgTe CQDs with high aspect ratios exhibit relatively strong photoconductivity response and are promising for CQD-based infrared photodetectors.
{"title":"HgTe colloidal quantum dot tripods for infrared photodetection","authors":"Shea Sanvordenker, Jungchul Noh, Jamie Howell, R. Pimpinella, B. Korgel","doi":"10.1117/12.2677860","DOIUrl":"https://doi.org/10.1117/12.2677860","url":null,"abstract":"Mercury telluride (HgTe) nanocrystal quantum dot-based infrared photodetectors provide a low-cost alternative to mercury cadmium telluride (MCT) bulk alloy devices made through epitaxial growth methods. The size-tunable optical properties of HgTe colloidal quantum dots (CQDs) make it possible to synthetically target a range of absorption edge wavelengths encompassing the infrared region. In this work, we report the synthesis of HgTe CQDs with high aspect ratios using solution-based colloidal techniques. The radial diameter of the arms of tripodal HgTe CQDs can be adjusted between 3 and 7 nm, with corresponding decreases in aspect ratios (arm length/radial diameter) from six to two, respectively. Tripodal HgTe CQDs exhibit room temperature photoconductivity with optical response ranging from the short wavelength infrared (SWIR) to mid-wavelength infrared (MWIR) spectral region, with optical cutoffs increasing from 1.7 to 3.5 µm with increasing CQD arm diameter. These tripodal HgTe CQDs with high aspect ratios exhibit relatively strong photoconductivity response and are promising for CQD-based infrared photodetectors.","PeriodicalId":13820,"journal":{"name":"International Conference on Nanoscience, Engineering and Technology (ICONSET 2011)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88725226","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}
This paper discusses the analysis of FeFET for low-power applications. The persistent scaling of computer capacity is necessary to handle the data's rapidly rising volume and complexity. CMOS technology's opportunities are shrinking as transistor size reduction approaches physical constraints. The new nanotechnologies have ability to replace the currently used CMOS and other technologies in energy-efficient computer devices. For information systems, ferroelectric FETs (FeFETs) are a potential candidate to continue improving power consumption. The FeFET analysis is carried out by evaluating drain current, transconductance, electric field, acceptor concentrations, and electric potential. Due to their energy, area efficiency and combined logic-memory functions, FeFETs, at the edge of semiconductor technology, are capable of meeting the requirements of integrated data computer applications. The proposed FeFET device has high ON current and small OFF current. The device exhibits a sub-threshold slope of 9.3 mV/dec, and the threshold voltage of 0.26 V. The proposed structure of FeFET is designed and simulated using the Silvaco TCAD tool. Proposed FeFET devices provides high-density and low-power circuit applications and would act as a promising candidate for the scientific and research community working in this area.
{"title":"FeFET device structure design and analysis for low power circuit applications","authors":"Mandeep Singh, T. Chaudhary, B. Raj","doi":"10.1117/12.2678161","DOIUrl":"https://doi.org/10.1117/12.2678161","url":null,"abstract":"This paper discusses the analysis of FeFET for low-power applications. The persistent scaling of computer capacity is necessary to handle the data's rapidly rising volume and complexity. CMOS technology's opportunities are shrinking as transistor size reduction approaches physical constraints. The new nanotechnologies have ability to replace the currently used CMOS and other technologies in energy-efficient computer devices. For information systems, ferroelectric FETs (FeFETs) are a potential candidate to continue improving power consumption. The FeFET analysis is carried out by evaluating drain current, transconductance, electric field, acceptor concentrations, and electric potential. Due to their energy, area efficiency and combined logic-memory functions, FeFETs, at the edge of semiconductor technology, are capable of meeting the requirements of integrated data computer applications. The proposed FeFET device has high ON current and small OFF current. The device exhibits a sub-threshold slope of 9.3 mV/dec, and the threshold voltage of 0.26 V. The proposed structure of FeFET is designed and simulated using the Silvaco TCAD tool. Proposed FeFET devices provides high-density and low-power circuit applications and would act as a promising candidate for the scientific and research community working in this area.","PeriodicalId":13820,"journal":{"name":"International Conference on Nanoscience, Engineering and Technology (ICONSET 2011)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80007664","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, we quantify the non-uniformity in the spin current density generated by spin-orbit torque (SOT) at the nanoscale and its impact on the switching of SOT magnetic random-access memories (MRAMs). In recent years, SOTMRAMs have emerged as promising non-volatile candidates for last-level (L3/L4) cache due to their high endurance, sufficiently low read/write latency, long retention times, and scalability. In these devices, a conduction current is passed through the non-magnetic (NM) layer, which generates a spin current flowing towards the ferromagnetic (FM) layer due to the Spin Hall Effect (SHE). Using conventional drift-diffusion models, which consider the electric current distribution to be uniform within the FM and NM layers, can lead to erroneous results in the case of nanoscale devices. In this paper, we use the spin current distribution calculated based on finite element simulations and drift-diffusion equations in micromagnetic simulation. We demonstrate that spin current density can be significantly lower at the two edges of the magnet compared to the middle and this non-uniformity can affect the magnet switching dynamics. We investigate the impact of this non-uniformity for both perpendicular magnetic anisotropy (PMA) and in-plane magnetic anisotropy (IMA) based magnetic tunnel junctions (MTJs). Our results show that when resistive NM layers are used, the impact of nonuniform spin current density on write times is more significant for larger FMs. In addition, the variation in write times is more significant in the case of PMA FM than IMA FM.
{"title":"Investigation on the impact of spin current profile on the write time of SOT MRAMs","authors":"Nahid Haque Shazon, Piyush Kumar, A. Naeemi","doi":"10.1117/12.2692161","DOIUrl":"https://doi.org/10.1117/12.2692161","url":null,"abstract":"In this work, we quantify the non-uniformity in the spin current density generated by spin-orbit torque (SOT) at the nanoscale and its impact on the switching of SOT magnetic random-access memories (MRAMs). In recent years, SOTMRAMs have emerged as promising non-volatile candidates for last-level (L3/L4) cache due to their high endurance, sufficiently low read/write latency, long retention times, and scalability. In these devices, a conduction current is passed through the non-magnetic (NM) layer, which generates a spin current flowing towards the ferromagnetic (FM) layer due to the Spin Hall Effect (SHE). Using conventional drift-diffusion models, which consider the electric current distribution to be uniform within the FM and NM layers, can lead to erroneous results in the case of nanoscale devices. In this paper, we use the spin current distribution calculated based on finite element simulations and drift-diffusion equations in micromagnetic simulation. We demonstrate that spin current density can be significantly lower at the two edges of the magnet compared to the middle and this non-uniformity can affect the magnet switching dynamics. We investigate the impact of this non-uniformity for both perpendicular magnetic anisotropy (PMA) and in-plane magnetic anisotropy (IMA) based magnetic tunnel junctions (MTJs). Our results show that when resistive NM layers are used, the impact of nonuniform spin current density on write times is more significant for larger FMs. In addition, the variation in write times is more significant in the case of PMA FM than IMA FM.","PeriodicalId":13820,"journal":{"name":"International Conference on Nanoscience, Engineering and Technology (ICONSET 2011)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75637566","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}
R. K. Raj, Ravi Shankar Verma, Shailendra Yadav, B. Kaushik
The magnetic skyrmion has distinct features like nanoscale size, particle-like behavior, low driving current, and topologically stable which makes it a suitable candidate for neuromorphic computing. Synthetic antiferromagnetic (SAF) skyrmions consist of a pair of coupled ferromagnetic (FM) skyrmions, each in its respective sub-layers that are favourable over the FM skyrmions as they follow the straight trajectories and prevent its annihilation at the nanotrack edge. In this work, a leaky integrate and fire neuronal device model is proposed based on SAF skyrmions with voltage control magnetic anisotropy (VCMA) as a leaky effect for the tunability of the device. The anisotropy is directly correlated with the size of the skyrmion meaning that in the region with larger anisotropy, the skyrmion size is smaller and hence, more energy. However, the skyrmions have the tendency to move toward the minimum energy state means it will move towards the lower anisotropy. This behavior of SAF skyrmion on a nanotrack with anisotropy gradient corresponds to the leaky-integrate-fire (LIF) functionality of the neuron device. Moreover, device performance is also realized at room temperature for practical implementation. Hence, the proposed device possesses an energy-efficient artificial neuron opens up the path for the development of next-generation skyrmionic devices for neuromorphic computing.
{"title":"SAF skyrmion-based leaky-integrate fire neuron device","authors":"R. K. Raj, Ravi Shankar Verma, Shailendra Yadav, B. Kaushik","doi":"10.1117/12.2681617","DOIUrl":"https://doi.org/10.1117/12.2681617","url":null,"abstract":"The magnetic skyrmion has distinct features like nanoscale size, particle-like behavior, low driving current, and topologically stable which makes it a suitable candidate for neuromorphic computing. Synthetic antiferromagnetic (SAF) skyrmions consist of a pair of coupled ferromagnetic (FM) skyrmions, each in its respective sub-layers that are favourable over the FM skyrmions as they follow the straight trajectories and prevent its annihilation at the nanotrack edge. In this work, a leaky integrate and fire neuronal device model is proposed based on SAF skyrmions with voltage control magnetic anisotropy (VCMA) as a leaky effect for the tunability of the device. The anisotropy is directly correlated with the size of the skyrmion meaning that in the region with larger anisotropy, the skyrmion size is smaller and hence, more energy. However, the skyrmions have the tendency to move toward the minimum energy state means it will move towards the lower anisotropy. This behavior of SAF skyrmion on a nanotrack with anisotropy gradient corresponds to the leaky-integrate-fire (LIF) functionality of the neuron device. Moreover, device performance is also realized at room temperature for practical implementation. Hence, the proposed device possesses an energy-efficient artificial neuron opens up the path for the development of next-generation skyrmionic devices for neuromorphic computing.","PeriodicalId":13820,"journal":{"name":"International Conference on Nanoscience, Engineering and Technology (ICONSET 2011)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83132734","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}
With the technological advancements in machine learning, it has become more prevalent to use learning techniques for clinical decision-making based on medical images. One of the state-of-the-art methods used for this purpose is Convolutional Neural Networks (CNN) for medical image segmentation and deep learning models for disease detection and classification. In this paper, we propose a framework for image segmentation using hierarchical CNNs to classify different types of cells using small frame images. This paper aims to generalize the segmentation of cancer cells, starting with cervix cancer. The first step of the framework is to achieve automatic nucleus and cell masking of the images using U-Net. The images are then segmented into “satisfactory” and “unsatisfactory” categories to determine whether these images can be used in our classification model. Using the hierarchical CNN, the satisfactory images are clustered based on cell types since the cell features that need to be considered vary between different cell types. Lastly, our classification model is trained with automatically segmented images to classify different cancer types based on cell images using various features, such as the area of the nucleus, the ratio of the nucleus area and cytoplasm area and the visual morphology of chromatin strands in the nucleus. To demonstrate the performance of the proposed framework, a labeled dataset, taken from the Detay Pathology and Cytology Laboratory, with over 100 images were used.
{"title":"Cell classification framework using U-Net: convolutional networks for cervix cell segmentation","authors":"Tugce Ermis, Emre Şener, M. Elitaş","doi":"10.1117/12.2677423","DOIUrl":"https://doi.org/10.1117/12.2677423","url":null,"abstract":"With the technological advancements in machine learning, it has become more prevalent to use learning techniques for clinical decision-making based on medical images. One of the state-of-the-art methods used for this purpose is Convolutional Neural Networks (CNN) for medical image segmentation and deep learning models for disease detection and classification. In this paper, we propose a framework for image segmentation using hierarchical CNNs to classify different types of cells using small frame images. This paper aims to generalize the segmentation of cancer cells, starting with cervix cancer. The first step of the framework is to achieve automatic nucleus and cell masking of the images using U-Net. The images are then segmented into “satisfactory” and “unsatisfactory” categories to determine whether these images can be used in our classification model. Using the hierarchical CNN, the satisfactory images are clustered based on cell types since the cell features that need to be considered vary between different cell types. Lastly, our classification model is trained with automatically segmented images to classify different cancer types based on cell images using various features, such as the area of the nucleus, the ratio of the nucleus area and cytoplasm area and the visual morphology of chromatin strands in the nucleus. To demonstrate the performance of the proposed framework, a labeled dataset, taken from the Detay Pathology and Cytology Laboratory, with over 100 images were used.","PeriodicalId":13820,"journal":{"name":"International Conference on Nanoscience, Engineering and Technology (ICONSET 2011)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77467835","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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