S. Dinarelli, A. Sikora, A. Sorbo, M. Rossi, D. Passeri
The design, optimization, and realization of innovative nanocomposite materials for advanced applications in a broad range of fields, from energy, automotive, photonics, to biology and nanomedicine require the capability to characterize their physical (e.g., mechanical, electric, magnetic...) properties from a multiscale perspective, in particular, not only at the macroscopic scale, but also at the nanometer one. In particular, methods are needed to characterize mechanical properties with nanometer lateral resolution, in order to understand the contribution of the nanosized features of the materials and the related phenomena. Atomic force microscopy (AFM) has been evolved from a tool for the morphological analysis of the sample surface to an integrated platform for the physicochemical characterization of samples. Current AFM systems host several advanced techniques for the mechanical characterization of materials with high speed and high lateral resolution in a broad range of mechanical moduli, e.g., from stiff samples (e.g., coatings, crystals…) to soft materials (e.g., polymers, biological samples...), in different environments (e.g., air, vacuum, liquid), and conditions (controlled humidity, controlled temperature). Here, short review of AFM based methods for the nanomechanical characterization of materials, in particular force spectroscopy, is reported, with emphasis on the materials which can be analyzed.
{"title":"Atomic force microscopy as a tool for mechanical characterizations at the nanometer scale","authors":"S. Dinarelli, A. Sikora, A. Sorbo, M. Rossi, D. Passeri","doi":"10.1680/jnaen.23.00016","DOIUrl":"https://doi.org/10.1680/jnaen.23.00016","url":null,"abstract":"The design, optimization, and realization of innovative nanocomposite materials for advanced applications in a broad range of fields, from energy, automotive, photonics, to biology and nanomedicine require the capability to characterize their physical (e.g., mechanical, electric, magnetic...) properties from a multiscale perspective, in particular, not only at the macroscopic scale, but also at the nanometer one. In particular, methods are needed to characterize mechanical properties with nanometer lateral resolution, in order to understand the contribution of the nanosized features of the materials and the related phenomena. Atomic force microscopy (AFM) has been evolved from a tool for the morphological analysis of the sample surface to an integrated platform for the physicochemical characterization of samples. Current AFM systems host several advanced techniques for the mechanical characterization of materials with high speed and high lateral resolution in a broad range of mechanical moduli, e.g., from stiff samples (e.g., coatings, crystals…) to soft materials (e.g., polymers, biological samples...), in different environments (e.g., air, vacuum, liquid), and conditions (controlled humidity, controlled temperature). Here, short review of AFM based methods for the nanomechanical characterization of materials, in particular force spectroscopy, is reported, with emphasis on the materials which can be analyzed.","PeriodicalId":44365,"journal":{"name":"Nanomaterials and Energy","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44386954","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}
CuSn10 alloy, has remarkable mechanical properties, including good elongation and medium hardness. Additive manufacturing of this powder compound is developing on a fast slope. In this paper, the optimization of the process parameters of the Selective Laser Melting (SLM) method was carried out to manufacture CuSn10 compounds. In addition, a numerical model for the simulation of the melt pool behaviour was created by utilizing Ansys 2021 R1 software, and a comparison was carried out between predicted numerical data with achieved experimental results. The formation conditions of various melt traces were modelled, measured, and validated for this aim. In the experimental stage, a constant laser power of 95 W was used, and the effect of variation of the scanning speed was studied between 10 to 1500 mm.s−1. Results showed that the variation of the scanning speed is not enough, and optimisation must be applied by participating in other process parameters. It indicates that by adjusting the process parameters to have a 365 W power, the liquid phase can be achieved in the production process.
{"title":"Influence investigation of the melt track geometry during selective laser melting of CuSn10","authors":"F. Foadian, A. T. Tabrizi, R. Kremer, H. Aghajani","doi":"10.1680/jnaen.23.00008","DOIUrl":"https://doi.org/10.1680/jnaen.23.00008","url":null,"abstract":"CuSn10 alloy, has remarkable mechanical properties, including good elongation and medium hardness. Additive manufacturing of this powder compound is developing on a fast slope. In this paper, the optimization of the process parameters of the Selective Laser Melting (SLM) method was carried out to manufacture CuSn10 compounds. In addition, a numerical model for the simulation of the melt pool behaviour was created by utilizing Ansys 2021 R1 software, and a comparison was carried out between predicted numerical data with achieved experimental results. The formation conditions of various melt traces were modelled, measured, and validated for this aim. In the experimental stage, a constant laser power of 95 W was used, and the effect of variation of the scanning speed was studied between 10 to 1500 mm.s−1. Results showed that the variation of the scanning speed is not enough, and optimisation must be applied by participating in other process parameters. It indicates that by adjusting the process parameters to have a 365 W power, the liquid phase can be achieved in the production process.","PeriodicalId":44365,"journal":{"name":"Nanomaterials and Energy","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46052279","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}
E. Mohapatra, J. Jena, Devika Jena, Sanghamitra Das, Tara Prasanna Dash
Gate-all-around Nanosheet field-effect transistor (GAA-NSFET) is a potential replacement for the state-of-art FinFET devices at advanced technology nodes. In this article, the impact of process-induced variability such as gate work function variation (WFV) on NSFETs using 3D TCAD numerical device simulation is studied. The WFV of NSFETs and NWFETs using multiple stack channels are also analyzed. The fluctuation in the threshold voltage (σVTH) and on-current (σION) of NSFETs is mainly affected by the WFV of the metal gate. It is investigated that single and 3-stacked NSFET shows superior immunity to WFV compared to NWFET. Furthermore, a layout-based NSFET inverter design using the DTCO technique is followed and the advantages of the stacked NSFET in terms of delay, power dissipation and switching energy are also reported.
{"title":"Design technique co-optimization approach to GAA FETs for inverter design at advanced technology node","authors":"E. Mohapatra, J. Jena, Devika Jena, Sanghamitra Das, Tara Prasanna Dash","doi":"10.1680/jnaen.23.00029","DOIUrl":"https://doi.org/10.1680/jnaen.23.00029","url":null,"abstract":"Gate-all-around Nanosheet field-effect transistor (GAA-NSFET) is a potential replacement for the state-of-art FinFET devices at advanced technology nodes. In this article, the impact of process-induced variability such as gate work function variation (WFV) on NSFETs using 3D TCAD numerical device simulation is studied. The WFV of NSFETs and NWFETs using multiple stack channels are also analyzed. The fluctuation in the threshold voltage (σVTH) and on-current (σION) of NSFETs is mainly affected by the WFV of the metal gate. It is investigated that single and 3-stacked NSFET shows superior immunity to WFV compared to NWFET. Furthermore, a layout-based NSFET inverter design using the DTCO technique is followed and the advantages of the stacked NSFET in terms of delay, power dissipation and switching energy are also reported.","PeriodicalId":44365,"journal":{"name":"Nanomaterials and Energy","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43267559","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}
Implementing the integrated computational materials engineering methodology in modeling plastic deformation processes and associated phenomena can provide a unique opportunity for a deeper study of material behavior at smaller scales and result in more precise and accurate predictions. This study presents a multiscale modeling framework linking two different length scales – namely, the electronic and the atomic scale – to investigate the mechanical properties of pure aluminum (Al) and to achieve the required parameters and information for higher scales. At the electronic scale, the elastic properties and interfacial energies for aluminum were garnered from density functional theory simulations to calibrate the modified embedded atom method (MEAM) potentials required for atomic simulations. The calculation for the generalized stacking fault energy resulted in an intrinsic stacking fault energy of 185.5 mJ/m2. Using the parameter calculated at the electronic scale as well as the MEAM potential parameters, the edge dislocation mobility of aluminum from molecular dynamics simulations was calculated at the atomic scale (nano). A drag coefficient of 7.3 × 10−5 Pa s was computed at 300 K. The dependency of the drag coefficient on the temperature was also studied, and the results showed that the velocity linearly depended on τ/T up to 0.4 MPa/K.
在塑性变形过程和相关现象建模中实施综合计算材料工程方法，可以为在更小尺度上对材料行为进行更深入的研究提供独特的机会，并导致更精确和准确的预测。本研究提出了一个连接两个不同长度尺度(即电子和原子尺度)的多尺度建模框架，以研究纯铝(Al)的机械性能，并获得更高尺度所需的参数和信息。在电子尺度上，通过密度泛函理论模拟获得了铝的弹性性能和界面能，以校准原子模拟所需的修饰嵌入原子法(MEAM)电位。通过广义层错能的计算，得到层错能的本征值为185.5 mJ/m2。利用电子尺度上的参数和MEAM电位参数，在原子尺度(纳米)上计算了分子动力学模拟中铝的边缘位错迁移率。300 K时的阻力系数为7.3 × 10−5 Pa s。研究了阻力系数与温度的关系，结果表明，在0.4 MPa/K以内，速度与τ/T呈线性关系。
{"title":"Mechanical properties of aluminum through electronic- and atomic-scale simulations","authors":"S. Khani, H. Palkowski","doi":"10.1680/jnaen.23.00017","DOIUrl":"https://doi.org/10.1680/jnaen.23.00017","url":null,"abstract":"Implementing the integrated computational materials engineering methodology in modeling plastic deformation processes and associated phenomena can provide a unique opportunity for a deeper study of material behavior at smaller scales and result in more precise and accurate predictions. This study presents a multiscale modeling framework linking two different length scales – namely, the electronic and the atomic scale – to investigate the mechanical properties of pure aluminum (Al) and to achieve the required parameters and information for higher scales. At the electronic scale, the elastic properties and interfacial energies for aluminum were garnered from density functional theory simulations to calibrate the modified embedded atom method (MEAM) potentials required for atomic simulations. The calculation for the generalized stacking fault energy resulted in an intrinsic stacking fault energy of 185.5 mJ/m2. Using the parameter calculated at the electronic scale as well as the MEAM potential parameters, the edge dislocation mobility of aluminum from molecular dynamics simulations was calculated at the atomic scale (nano). A drag coefficient of 7.3 × 10−5 Pa s was computed at 300 K. The dependency of the drag coefficient on the temperature was also studied, and the results showed that the velocity linearly depended on τ/T up to 0.4 MPa/K.","PeriodicalId":44365,"journal":{"name":"Nanomaterials and Energy","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42312922","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 presents two thermal fatigue tests developed to simulate the typical thermal fatigue behavior of hot work tools and rolls. The tests were carried out on the Gleeble 1500D thermomechanical simulator with computer-controlled heating and cooling of the test specimens. In the first test, internal cooling of the specimens is performed, and in the second test, an external one. This allows constant test conditions and the collection of reliable experimental data on the thermal fatigue behaviour. The internally cooled test rig is used for testing the thermal fatigue properties of bulk materials. ICDP cast iron was used to present the basic capabilities of the test. At the material, the cracks take flattened graphite – cementite pathways. The external cooling test rig, on the other hand was designed for comparative testing of four surface simultaneously. Thus, the capabilities of the second test were presented in the comparative testing of three different laser-welded functionally graded material surface layers and the basic H13 tool steel, simultaneously. The highest thermal fatigue resistance exhibited the weld with the lowest Si content. A quantitative evaluation of thermal fatigue resistance as well as following of degradation processes at both tests is enabled.
{"title":"Thermal fatigue testing with repeatable temperature cycles on thermomechanical simulator Gleeble 1500D","authors":"P. Fajfar, D. Bombač, G. Kugler, M. Tercelj","doi":"10.1680/jnaen.23.00012","DOIUrl":"https://doi.org/10.1680/jnaen.23.00012","url":null,"abstract":"This paper presents two thermal fatigue tests developed to simulate the typical thermal fatigue behavior of hot work tools and rolls. The tests were carried out on the Gleeble 1500D thermomechanical simulator with computer-controlled heating and cooling of the test specimens. In the first test, internal cooling of the specimens is performed, and in the second test, an external one. This allows constant test conditions and the collection of reliable experimental data on the thermal fatigue behaviour. The internally cooled test rig is used for testing the thermal fatigue properties of bulk materials. ICDP cast iron was used to present the basic capabilities of the test. At the material, the cracks take flattened graphite – cementite pathways. The external cooling test rig, on the other hand was designed for comparative testing of four surface simultaneously. Thus, the capabilities of the second test were presented in the comparative testing of three different laser-welded functionally graded material surface layers and the basic H13 tool steel, simultaneously. The highest thermal fatigue resistance exhibited the weld with the lowest Si content. A quantitative evaluation of thermal fatigue resistance as well as following of degradation processes at both tests is enabled.","PeriodicalId":44365,"journal":{"name":"Nanomaterials and Energy","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42563952","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}
Doping of Cesium Lead Bromide (CsPbBr3) perovskite nanocrystals offers the effective control on the optical and optoelectrical properties leading to possibilities for several new applications. Herein, CsPbBr3 perovskite nanocrystals are synthesised with low concentration of Manganese (Mn) doping into perovskite lattice using Manganese chloride (MnCl2) precursor. A shift in x-ray diffraction peaks towards higher angles indicates that Mn as a dopant is present inside CsPbBr3 lattice. The change in the MnCl2 precursor concentration from 5 to 10 mmol, results an increment in the atomic percentage (At.%) of Mn from 0.3 to 0.5% into the CsPbBr3 crystal. Low concentration of Mn doping (0.3 At.%) in CsPbBr3 results in enhancement of green emission, while higher Mn doping (0.5 At.%) results in blue emission. The band gap of CsPbBr3 nanocrystals increases from 2.31 eV to 2.53 eV with increase in the concentration of manganese. The dark and photoelectrical conductivity of CsPbBr3 nanocrystals is improved in case of low concentration (0.3 At.%) of Mn doping. The ratio of photocurrent vs. dark current is found to be ∼182 in Mn doped CsPbBr3 crystals film as compared to ∼101 for undoped CsPbBr3 crystals film. The low concentration of Mn doping improves the overall electrical and photoelectrical conductivity of CsPbBr3 perovskite nanocrystals.
{"title":"Green emission and photoelectrical properties of low concentration Mn doped CsPbBr3 nanocrystals","authors":"A. Bhardwaj, A. Kushwaha","doi":"10.1680/jnaen.22.00062","DOIUrl":"https://doi.org/10.1680/jnaen.22.00062","url":null,"abstract":"Doping of Cesium Lead Bromide (CsPbBr3) perovskite nanocrystals offers the effective control on the optical and optoelectrical properties leading to possibilities for several new applications. Herein, CsPbBr3 perovskite nanocrystals are synthesised with low concentration of Manganese (Mn) doping into perovskite lattice using Manganese chloride (MnCl2) precursor. A shift in x-ray diffraction peaks towards higher angles indicates that Mn as a dopant is present inside CsPbBr3 lattice. The change in the MnCl2 precursor concentration from 5 to 10 mmol, results an increment in the atomic percentage (At.%) of Mn from 0.3 to 0.5% into the CsPbBr3 crystal. Low concentration of Mn doping (0.3 At.%) in CsPbBr3 results in enhancement of green emission, while higher Mn doping (0.5 At.%) results in blue emission. The band gap of CsPbBr3 nanocrystals increases from 2.31 eV to 2.53 eV with increase in the concentration of manganese. The dark and photoelectrical conductivity of CsPbBr3 nanocrystals is improved in case of low concentration (0.3 At.%) of Mn doping. The ratio of photocurrent vs. dark current is found to be ∼182 in Mn doped CsPbBr3 crystals film as compared to ∼101 for undoped CsPbBr3 crystals film. The low concentration of Mn doping improves the overall electrical and photoelectrical conductivity of CsPbBr3 perovskite nanocrystals.","PeriodicalId":44365,"journal":{"name":"Nanomaterials and Energy","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67489333","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}
During the past few years, halide double perovskites have been extensively explored for designing eco-friendly and stable perovskite-family absorber materials. In this work, thin films of Cs2AgBiBr6 double perovskites were successfully fabricated with the aim of obtaining a lead-free system. Optical studies confirmed the large band gap of 2.33 eV of Cs2AgBiBr6 films. Post-synthetic vapor treatment of Cs2AgBiBr6 thin films, with tin (IV) iodide (SnI4; SI), was performed to engineer their optical response. Structural and optical studies confirmed the phase purity of the various SI-treated films. X-ray diffraction studies further showed a systematic shift toward lower 2θ values, which signified the expansion of lattice parameters on SI substitution in the Cs2AgBiBr6 structure. The as-prepared pristine and SI-treated films showed good coverage with a reasonably large grain size. Furthermore, the optical studies revealed a 0.47 eV reduction in the band gap of SI-treated films, as opposed to a small band-gap change of approximately 0.22 eV when the pristine Cs2AgBiBr6 film was treated with cesium iodide (CsI). This showed the role of the combined effects of charge-balancing defects and compositional substitution in band-gap lowering in Cs2AgBiBr6. The controlled doping in lead-free double perovskites for improved optical properties might help in strengthening their use for future optoelectronic applications.
{"title":"Anion/cation substitution in lead-free double-perovskite films: for band-gap optimization","authors":"Bhawna, A. Alam, M. Aslam","doi":"10.1680/jnaen.23.00001","DOIUrl":"https://doi.org/10.1680/jnaen.23.00001","url":null,"abstract":"During the past few years, halide double perovskites have been extensively explored for designing eco-friendly and stable perovskite-family absorber materials. In this work, thin films of Cs2AgBiBr6 double perovskites were successfully fabricated with the aim of obtaining a lead-free system. Optical studies confirmed the large band gap of 2.33 eV of Cs2AgBiBr6 films. Post-synthetic vapor treatment of Cs2AgBiBr6 thin films, with tin (IV) iodide (SnI4; SI), was performed to engineer their optical response. Structural and optical studies confirmed the phase purity of the various SI-treated films. X-ray diffraction studies further showed a systematic shift toward lower 2θ values, which signified the expansion of lattice parameters on SI substitution in the Cs2AgBiBr6 structure. The as-prepared pristine and SI-treated films showed good coverage with a reasonably large grain size. Furthermore, the optical studies revealed a 0.47 eV reduction in the band gap of SI-treated films, as opposed to a small band-gap change of approximately 0.22 eV when the pristine Cs2AgBiBr6 film was treated with cesium iodide (CsI). This showed the role of the combined effects of charge-balancing defects and compositional substitution in band-gap lowering in Cs2AgBiBr6. The controlled doping in lead-free double perovskites for improved optical properties might help in strengthening their use for future optoelectronic applications.","PeriodicalId":44365,"journal":{"name":"Nanomaterials and Energy","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42927306","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}
Mixed-halide perovskites offer the important characteristic of band-gap tunability, which is essential for tandem solar cells. Herein, the single-source vapor deposition method is reported for MAPbBr2Cl1 (MA (methyl ammonium) = CH3NH3), MAPbBr1.5Cl1.5 and MAPbBr1Cl2 perovskite films utilizing the corresponding mixed-halide perovskite nanoparticles as a source for thermal evaporation. Further, band-gap tuning in vacuum-deposited MAPbBr3 thin films is performed through MACl treatment with successful band-gap tuning from 2.37 to 2.48 eV. The limitation of chlorine (Cl) incorporation into the perovskite structure at room temperature is tackled by MACl treatment of vapor-deposited MAPbBr2Cl1, MAPbBr1.5Cl1.5 and MAPbBr1Cl2 films. The structural properties of MAPbBr3−x Cl x films show a continuous shift in the X-ray diffraction peak toward a higher 2θ value, confirming chlorine incorporation into the perovskite structure. Band-gap tuning in MAPbBr3−x Cl x films, from 2.37 to 2.86 eV, is confirmed by absorption spectroscopy. The mixed-halide perovskite films show an improved microstructure with MACl treatment, as observed from the increased grain size of the films. Further, emission studies show good stability of MAPbBr3−x Cl x films against phase segregation under continuous exposure to 325 nm wavelength illumination of 100 mW/cm2 for more than 60 min. The diminished phase segregation might help in advancing the application of mixed-halide perovskites for reliable optoelectronic devices.
{"title":"Band-gap-engineered mixed-halide perovskite films through vacuum-based deposition approach","authors":"Rekha Yadav, Gangadhar Banappanavar, M. Aslam","doi":"10.1680/jnaen.23.00003","DOIUrl":"https://doi.org/10.1680/jnaen.23.00003","url":null,"abstract":"Mixed-halide perovskites offer the important characteristic of band-gap tunability, which is essential for tandem solar cells. Herein, the single-source vapor deposition method is reported for MAPbBr2Cl1 (MA (methyl ammonium) = CH3NH3), MAPbBr1.5Cl1.5 and MAPbBr1Cl2 perovskite films utilizing the corresponding mixed-halide perovskite nanoparticles as a source for thermal evaporation. Further, band-gap tuning in vacuum-deposited MAPbBr3 thin films is performed through MACl treatment with successful band-gap tuning from 2.37 to 2.48 eV. The limitation of chlorine (Cl) incorporation into the perovskite structure at room temperature is tackled by MACl treatment of vapor-deposited MAPbBr2Cl1, MAPbBr1.5Cl1.5 and MAPbBr1Cl2 films. The structural properties of MAPbBr3−x Cl x films show a continuous shift in the X-ray diffraction peak toward a higher 2θ value, confirming chlorine incorporation into the perovskite structure. Band-gap tuning in MAPbBr3−x Cl x films, from 2.37 to 2.86 eV, is confirmed by absorption spectroscopy. The mixed-halide perovskite films show an improved microstructure with MACl treatment, as observed from the increased grain size of the films. Further, emission studies show good stability of MAPbBr3−x Cl x films against phase segregation under continuous exposure to 325 nm wavelength illumination of 100 mW/cm2 for more than 60 min. The diminished phase segregation might help in advancing the application of mixed-halide perovskites for reliable optoelectronic devices.","PeriodicalId":44365,"journal":{"name":"Nanomaterials and Energy","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42613759","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, SiO2/TiO2 multilayer films were deposited on silicon substrates via sol-gel spin-coating techniques with the precursors of titanium butoxide and tetraethyl orthosilicate. After the preparation studied the various optical and morphological properties by using X-ray diffractometer (XRD), Fourier transform infrared (FTIR) spectroscopy, and UV-Visible spectrometer. XRD patterns revealed the intense diffraction peaks which were found that the anatase-TiO2 and well-matched with the standard JCPDS file. With the intense peaks, calculated the crystallite size of the prepared samples are 24 nm for three stacks (3S)-SiO2/TiO2 and 30 nm for five stacks (5S)-SiO2/TiO2 thin films using Debye Scherrer’s formula.FTIR transmittance spectra were confirmed the Si-O-Ti vibrational modes at 800 and 960 cm−1 with related functional groups. The reflectance of 86% was noticed by UV-Visible spectrophotometer. These dielectric multipliers will be useful in solar cells as the backside reflectors for improved light-harvesting mechanism.
{"title":"Optical investigation of Sol-Gel synthesized and spin-coating SiO2/TiO2 multilayers","authors":"S. Saravanan, R. S. Dubey, P. Subbarao","doi":"10.1680/jnaen.22.00039","DOIUrl":"https://doi.org/10.1680/jnaen.22.00039","url":null,"abstract":"In this work, SiO2/TiO2 multilayer films were deposited on silicon substrates via sol-gel spin-coating techniques with the precursors of titanium butoxide and tetraethyl orthosilicate. After the preparation studied the various optical and morphological properties by using X-ray diffractometer (XRD), Fourier transform infrared (FTIR) spectroscopy, and UV-Visible spectrometer. XRD patterns revealed the intense diffraction peaks which were found that the anatase-TiO2 and well-matched with the standard JCPDS file. With the intense peaks, calculated the crystallite size of the prepared samples are 24 nm for three stacks (3S)-SiO2/TiO2 and 30 nm for five stacks (5S)-SiO2/TiO2 thin films using Debye Scherrer’s formula.FTIR transmittance spectra were confirmed the Si-O-Ti vibrational modes at 800 and 960 cm−1 with related functional groups. The reflectance of 86% was noticed by UV-Visible spectrophotometer. These dielectric multipliers will be useful in solar cells as the backside reflectors for improved light-harvesting mechanism.","PeriodicalId":44365,"journal":{"name":"Nanomaterials and Energy","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48498899","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}
Remya Simon, S. Chakraborty, A. V., Elias Jesu Packiam D., M. N. L.
Reliable energy storage materials which can provide enhanced capacitance with good cycling stability along with improved energy and power densities are exceedingly relevant in the commercial arena to attenuate the prevalent energy shortage. Polymers with structural flexibility and good mechanical and thermal stability can be coupled with carbon-based additives to obtain an electrochemical platform for energy storage without compromising on the required thermal and mechanical attributes. Here, styrene maleic-anhydride copolymer has been modified with a diamine to form a polyimide. These samples have been characterized using UV- Visible, 13C NMR, FTIR, FT Raman spectroscopy, TGA, DSC, BET, SEM, TEM and XRD techniques to understand and substantiate the spectral, morphological and electrochemical characteristics of the polymer nanocomposites. Efficacious intercalation of Graphene oxide has resulted in the formation of polymer nanocomposites which can act as excellent supercapacitor electrodes with a high specific capacitance of 700 F/g at 0.5 A/g and an energy and power density of 129.23 Wh kg−1 and 5572 Wkg−1 respectively.
{"title":"Graphene oxide doped poly (styrene-co-maleic anhydride) for high energy supercapacitors","authors":"Remya Simon, S. Chakraborty, A. V., Elias Jesu Packiam D., M. N. L.","doi":"10.1680/jnaen.22.00026","DOIUrl":"https://doi.org/10.1680/jnaen.22.00026","url":null,"abstract":"Reliable energy storage materials which can provide enhanced capacitance with good cycling stability along with improved energy and power densities are exceedingly relevant in the commercial arena to attenuate the prevalent energy shortage. Polymers with structural flexibility and good mechanical and thermal stability can be coupled with carbon-based additives to obtain an electrochemical platform for energy storage without compromising on the required thermal and mechanical attributes. Here, styrene maleic-anhydride copolymer has been modified with a diamine to form a polyimide. These samples have been characterized using UV- Visible, 13C NMR, FTIR, FT Raman spectroscopy, TGA, DSC, BET, SEM, TEM and XRD techniques to understand and substantiate the spectral, morphological and electrochemical characteristics of the polymer nanocomposites. Efficacious intercalation of Graphene oxide has resulted in the formation of polymer nanocomposites which can act as excellent supercapacitor electrodes with a high specific capacitance of 700 F/g at 0.5 A/g and an energy and power density of 129.23 Wh kg−1 and 5572 Wkg−1 respectively.","PeriodicalId":44365,"journal":{"name":"Nanomaterials and Energy","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44628114","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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