Pub Date : 2025-12-27DOI: 10.1016/j.micrna.2025.208544
Ishan Sodani, Girish Chandra Ghivela
The graphene, one of the most promising and wonder material of recent time, has transformed nanotechnology with its amazing electrical, mechanical, and optical qualities. Due to its potential for high sensitivity, real-time monitoring, and integration with contemporary wireless technologies, graphene-based microwave sensors have attracted a lot of attention recently. The conventional microwave sensors suffers from the drawbacks of larger size, a narrow frequency range, and decreased sensitivity in challenging conditions. However, graphene based microwave sensor is the best substitute to conventional one; thanks to its adjustable band gap and remarkable electronic properties. This article discuss the basics of graphene, its different synthesis processes, and its recent advancement in microwave sensors. The different microwave properties of graphene material includes microwave sensing, absorption, wave manipulation, and responsivity. Then, types of graphene based microwave sensors, its performance comparison and potential application in different sectors are focused. Finally, the current challenges and future directions are emphasized.
{"title":"Potentiality of graphene in microwave sensor: The current state of the art, challenges and future directions","authors":"Ishan Sodani, Girish Chandra Ghivela","doi":"10.1016/j.micrna.2025.208544","DOIUrl":"10.1016/j.micrna.2025.208544","url":null,"abstract":"<div><div>The graphene, one of the most promising and wonder material of recent time, has transformed nanotechnology with its amazing electrical, mechanical, and optical qualities. Due to its potential for high sensitivity, real-time monitoring, and integration with contemporary wireless technologies, graphene-based microwave sensors have attracted a lot of attention recently. The conventional microwave sensors suffers from the drawbacks of larger size, a narrow frequency range, and decreased sensitivity in challenging conditions. However, graphene based microwave sensor is the best substitute to conventional one; thanks to its adjustable band gap and remarkable electronic properties. This article discuss the basics of graphene, its different synthesis processes, and its recent advancement in microwave sensors. The different microwave properties of graphene material includes microwave sensing, absorption, wave manipulation, and responsivity. Then, types of graphene based microwave sensors, its performance comparison and potential application in different sectors are focused. Finally, the current challenges and future directions are emphasized.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"211 ","pages":"Article 208544"},"PeriodicalIF":3.0,"publicationDate":"2025-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145884781","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 : 2025-12-27DOI: 10.1016/j.micrna.2025.208541
Mirunalini Aravindan , C. Periasamy , Ramanand A.C. , Muneeswaran Packiaraj , S. Raghavan , Preeth Raguraman
This work presents the design and optimization of AlGaN/GaN based High Electron Mobility Transistors (HEMT) with an AlO functionalization layer for the detection of Heavy Metal Ions (HMIs) in water. Silvaco TCAD simulations were used to optimize the HEMT structure and to test its response to varying concentrations of mercury (Hg) and lead (Pb) ions. The obtained simulation results demonstrate that the AlO functionalized HEMT structure exhibits notable sensitivity of 0.48 mV/(mg/mL) and 0.452 mV/(mg/mL) for Hg and Pb ions, respectively. However, the selectivity of the proposed sensor between the two ions is poor, which poses a challenge for accurate discrimination between different heavy metal ions. To address this limitation, a machine learning-based approach was employed, utilizing key electrical characteristics such as threshold voltage (Vth) and saturation current () to improve ion differentiation and selectivity. This proposed ML method provides a generalizable strategy for simultaneous detection and multi-ion quantification of coexisting metal ions. The simulation study also indicated that the proposed AlO functionalized AlGaN/GaN HEMT based sensor has potential applications in mercury and lead ion detection in an aqueous environment.
{"title":"Design and simulation of HEMT-based sensor for Heavy Metal Ion detection with selectivity enhancement using ensemble methods","authors":"Mirunalini Aravindan , C. Periasamy , Ramanand A.C. , Muneeswaran Packiaraj , S. Raghavan , Preeth Raguraman","doi":"10.1016/j.micrna.2025.208541","DOIUrl":"10.1016/j.micrna.2025.208541","url":null,"abstract":"<div><div>This work presents the design and optimization of AlGaN/GaN based High Electron Mobility Transistors (HEMT) with an Al<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>O<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span> functionalization layer for the detection of Heavy Metal Ions (HMIs) in water. Silvaco TCAD simulations were used to optimize the HEMT structure and to test its response to varying concentrations of mercury (Hg<span><math><msup><mrow></mrow><mrow><mn>2</mn><mo>+</mo></mrow></msup></math></span>) and lead (Pb<span><math><msup><mrow></mrow><mrow><mn>2</mn><mo>+</mo></mrow></msup></math></span>) ions. The obtained simulation results demonstrate that the Al<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>O<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span> functionalized HEMT structure exhibits notable sensitivity of 0.48 mV/(mg/mL) and 0.452 mV/(mg/mL) for Hg<span><math><msup><mrow></mrow><mrow><mn>2</mn><mo>+</mo></mrow></msup></math></span> and Pb<span><math><msup><mrow></mrow><mrow><mn>2</mn><mo>+</mo></mrow></msup></math></span> ions, respectively. However, the selectivity of the proposed sensor between the two ions is poor, which poses a challenge for accurate discrimination between different heavy metal ions. To address this limitation, a machine learning-based approach was employed, utilizing key electrical characteristics such as threshold voltage (Vth) and saturation current (<span><math><msub><mrow><mi>I</mi></mrow><mrow><mi>D</mi><mi>S</mi><mi>S</mi></mrow></msub></math></span>) to improve ion differentiation and selectivity. This proposed ML method provides a generalizable strategy for simultaneous detection and multi-ion quantification of coexisting metal ions. The simulation study also indicated that the proposed Al<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>O<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span> functionalized AlGaN/GaN HEMT based sensor has potential applications in mercury and lead ion detection in an aqueous environment.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"211 ","pages":"Article 208541"},"PeriodicalIF":3.0,"publicationDate":"2025-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145884788","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 : 2025-12-26DOI: 10.1016/j.micrna.2025.208540
Ruiyuan Li, Lu Yang, Hang Su
This study investigates the optimization of the optoelectronic properties of GaSe/ZrS2 van der Waals heterostructures through oxygen atom doping and applied shear strain. Using first-principles calculations based on density functional theory, the band structure, charge distribution, and optical response of the system were compared under intrinsic, doped, and varying strain conditions. The results show that the heterostructure exhibits a reduced band gap of 0.811 eV compared to its monolayer constituents, leading to significantly enhanced visible light absorption. Upon oxygen doping, the band gap further decreases to 0.708 eV, accompanied by notable interfacial charge transfer. When a 2 % shear strain is applied along the y-x direction, the band gap reaches its maximum value, after which it gradually decreases with increasing strain, demonstrating anisotropic tunability. Density of states analysis confirms that both doping and shear strain effectively modulate the electronic structure of the heterostructure. The dielectric constant increases steadily with strain, and a redshift in the absorption edge is observed, indicating improved utilization of low-energy photons. Differential charge density analysis reveals that the coupled effect of strain and doping induces a stronger polarization effect at the interface. This study demonstrates that the synergistic strategy of nonmetal atom doping and shear strain enables precise atomic-scale control over the electronic structure and optical properties of two-dimensional heterostructures, providing theoretical support for the development of high-efficiency, flexible, and spectrally tunable thin-film photovoltaic and photodetection devices.
{"title":"Tuning the optoelectronic properties of GaSe/ZrS2 van der Waals heterojunctions via shear strain and non-metal doping","authors":"Ruiyuan Li, Lu Yang, Hang Su","doi":"10.1016/j.micrna.2025.208540","DOIUrl":"10.1016/j.micrna.2025.208540","url":null,"abstract":"<div><div>This study investigates the optimization of the optoelectronic properties of GaSe/ZrS<sub>2</sub> van der Waals heterostructures through oxygen atom doping and applied shear strain. Using first-principles calculations based on density functional theory, the band structure, charge distribution, and optical response of the system were compared under intrinsic, doped, and varying strain conditions. The results show that the heterostructure exhibits a reduced band gap of 0.811 eV compared to its monolayer constituents, leading to significantly enhanced visible light absorption. Upon oxygen doping, the band gap further decreases to 0.708 eV, accompanied by notable interfacial charge transfer. When a 2 % shear strain is applied along the y-x direction, the band gap reaches its maximum value, after which it gradually decreases with increasing strain, demonstrating anisotropic tunability. Density of states analysis confirms that both doping and shear strain effectively modulate the electronic structure of the heterostructure. The dielectric constant increases steadily with strain, and a redshift in the absorption edge is observed, indicating improved utilization of low-energy photons. Differential charge density analysis reveals that the coupled effect of strain and doping induces a stronger polarization effect at the interface. This study demonstrates that the synergistic strategy of nonmetal atom doping and shear strain enables precise atomic-scale control over the electronic structure and optical properties of two-dimensional heterostructures, providing theoretical support for the development of high-efficiency, flexible, and spectrally tunable thin-film photovoltaic and photodetection devices.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"211 ","pages":"Article 208540"},"PeriodicalIF":3.0,"publicationDate":"2025-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145884786","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 : 2025-12-26DOI: 10.1016/j.micrna.2025.208543
Jia-Qi Li, You Xie, Yan Chen, Jia-Hao Wang, Yi-An Liu, Li-Mei Hao, Tao Zhang
In this work, first-principles calculations were employed to systematically investigate the strain-modulated electronic structures, optical absorption, and photovoltaic performance of novel BP/XSi2N2P2van der Waals heterostructures (vdWHs) composed of boron phosphide (BP) and XSi2N2P2 (X = W/Mo) with two stacking configurations (a1, a2) under biaxial strains (−2 % compressive to 8 % tensile). Our results reveal that the stacking configuration dictates the bandgap nature of the vdWHs while preserving a favorable type-II band alignment across all strain conditions. The BP/XSi2N2P2-a1 has indirect bandgaps (0.67 eV for Mo, 0.74 eV for W), whereas a2 has direct bandgaps (0.96 eV for Mo, 1.21 eV for W), which are beneficial for light-to-electricity conversion. All BP/XSi2N2P2 vdWHs exhibit broad, intense ultraviolet–visible absorption; tensile strain induces redshift and enhanced ultraviolet absorption. Notably, under 2 % tensile strain, the BP/WSi2N2P2-a2 vdWH achieves ultrahigh power conversion efficiency (PCE) of 25.61 %, while the BP/MoSi2N2P2-a2 vdWH reaches a PCE of 20.18 %; this superior performance stems from optimized band alignment and a strengthened built-in electric field. Collectively, these findings lay a physical basis for BP/XSi2N2P2 vdWHs in optoelectronics and guide high-efficiency two-dimensional energy device design, highlighting stacking-strain synergy.
{"title":"First-principles study on biaxial strain-regulated photovoltaic performance of BP/XSi2N2P2 (X=W/Mo) heterostructures with distinct stacking configurations","authors":"Jia-Qi Li, You Xie, Yan Chen, Jia-Hao Wang, Yi-An Liu, Li-Mei Hao, Tao Zhang","doi":"10.1016/j.micrna.2025.208543","DOIUrl":"10.1016/j.micrna.2025.208543","url":null,"abstract":"<div><div>In this work, first-principles calculations were employed to systematically investigate the strain-modulated electronic structures, optical absorption, and photovoltaic performance of novel BP/XSi<sub>2</sub>N<sub>2</sub>P<sub>2</sub>van der Waals heterostructures (vdWHs) composed of boron phosphide (BP) and XSi<sub>2</sub>N<sub>2</sub>P<sub>2</sub> (X = W/Mo) with two stacking configurations (a<sub>1</sub>, a<sub>2</sub>) under biaxial strains (−2 % compressive to 8 % tensile). Our results reveal that the stacking configuration dictates the bandgap nature of the vdWHs while preserving a favorable type-II band alignment across all strain conditions. The BP/XSi<sub>2</sub>N<sub>2</sub>P<sub>2</sub>-a<sub>1</sub> has indirect bandgaps (0.67 eV for Mo, 0.74 eV for W), whereas a<sub>2</sub> has direct bandgaps (0.96 eV for Mo, 1.21 eV for W), which are beneficial for light-to-electricity conversion. All BP/XSi<sub>2</sub>N<sub>2</sub>P<sub>2</sub> vdWHs exhibit broad, intense ultraviolet–visible absorption; tensile strain induces redshift and enhanced ultraviolet absorption. Notably, under 2 % tensile strain, the BP/WSi<sub>2</sub>N<sub>2</sub>P<sub>2</sub>-a<sub>2</sub> vdWH achieves ultrahigh power conversion efficiency (PCE) of 25.61 %, while the BP/MoSi<sub>2</sub>N<sub>2</sub>P<sub>2</sub>-a<sub>2</sub> vdWH reaches a PCE of 20.18 %; this superior performance stems from optimized band alignment and a strengthened built-in electric field. Collectively, these findings lay a physical basis for BP/XSi<sub>2</sub>N<sub>2</sub>P<sub>2</sub> vdWHs in optoelectronics and guide high-efficiency two-dimensional energy device design, highlighting stacking-strain synergy.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"211 ","pages":"Article 208543"},"PeriodicalIF":3.0,"publicationDate":"2025-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145884782","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 : 2025-12-25DOI: 10.1016/j.micrna.2025.208538
Yihua He , Xin Liu , Guangjun Yu , Chi Liu , Tao Shen
This study employs density functional theory to investigate the adsorption properties of five toxic gases (CO, C2H2, CH4, NO2, NH3) on the surface of Ti2CO2 modified by transition metal Cun (n = 1–3) clusters. The optimal modification sites for Cun-Ti2CO2 clusters with n = 1, 2, and 3 were identified. Molecular dynamics simulations further confirmed the thermodynamic stability of the modified systems, with the binding energy reaching −3.698 eV when the cluster's atom count reached three. Based on this, the adsorption properties of five gases at optimal modification sites were systematically analyzed, including parameters such as adsorption distance, adsorption energy, charge transfer, density of states and work function sensitivity. Additionally, the changes in the system with the highest adsorption energy (Cu3–Ti2CO2/NH3) were investigated after applying biaxial strain. Results indicate that all systems modified with Cun clusters exhibit significantly enhanced adsorption performance and spontaneous adsorption stability; specifically, Cu1–Ti2CO2 shows 9.6 % sensitivity to NH3, while Cu2–Ti2CO2 reaches 9.1 % sensitivity to C2H2. Cu3–Ti2CO2 is considered a promising NH3 gas-sensitive material based on the parameters obtained. Notably, the Cu1–Ti2CO2 system exhibited an excellent recovery time of 12.6 s for NO2 at 498 K, demonstrating rapid response potential. This work elucidates the influence of copper atom number in the Cun-Ti2CO2 system on adsorption performance and electronic properties for toxic gases, providing a theoretical basis for their detection and removal.
{"title":"Adsorption properties of hazardous gases on Ti2CO2-MXenes modified by Cun (n=1–3) clusters: A DFT study","authors":"Yihua He , Xin Liu , Guangjun Yu , Chi Liu , Tao Shen","doi":"10.1016/j.micrna.2025.208538","DOIUrl":"10.1016/j.micrna.2025.208538","url":null,"abstract":"<div><div>This study employs density functional theory to investigate the adsorption properties of five toxic gases (CO, C<sub>2</sub>H<sub>2</sub>, CH<sub>4</sub>, NO<sub>2</sub>, NH<sub>3</sub>) on the surface of Ti<sub>2</sub>CO<sub>2</sub> modified by transition metal Cu<sub>n</sub> (n = 1–3) clusters. The optimal modification sites for Cu<sub>n</sub>-Ti<sub>2</sub>CO<sub>2</sub> clusters with n = 1, 2, and 3 were identified. Molecular dynamics simulations further confirmed the thermodynamic stability of the modified systems, with the binding energy reaching −3.698 eV when the cluster's atom count reached three. Based on this, the adsorption properties of five gases at optimal modification sites were systematically analyzed, including parameters such as adsorption distance, adsorption energy, charge transfer, density of states and work function sensitivity. Additionally, the changes in the system with the highest adsorption energy (Cu<sub>3</sub>–Ti<sub>2</sub>CO<sub>2</sub>/NH<sub>3</sub>) were investigated after applying biaxial strain. Results indicate that all systems modified with Cu<sub>n</sub> clusters exhibit significantly enhanced adsorption performance and spontaneous adsorption stability; specifically, Cu<sub>1</sub>–Ti<sub>2</sub>CO<sub>2</sub> shows 9.6 % sensitivity to NH<sub>3</sub>, while Cu<sub>2</sub>–Ti<sub>2</sub>CO<sub>2</sub> reaches 9.1 % sensitivity to C<sub>2</sub>H<sub>2</sub>. Cu<sub>3</sub>–Ti<sub>2</sub>CO<sub>2</sub> is considered a promising NH<sub>3</sub> gas-sensitive material based on the parameters obtained. Notably, the Cu<sub>1</sub>–Ti<sub>2</sub>CO<sub>2</sub> system exhibited an excellent recovery time of 12.6 s for NO<sub>2</sub> at 498 K, demonstrating rapid response potential. This work elucidates the influence of copper atom number in the Cu<sub>n</sub>-Ti<sub>2</sub>CO<sub>2</sub> system on adsorption performance and electronic properties for toxic gases, providing a theoretical basis for their detection and removal.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"211 ","pages":"Article 208538"},"PeriodicalIF":3.0,"publicationDate":"2025-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145841727","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 : 2025-12-24DOI: 10.1016/j.micrna.2025.208537
V.V. Manju , R. Sanjana , Vinayakprasanna N. Hegde , S. Divakara , B.C. Hemaraju , Janya Lumbini , Namratha , N. Raghu , R. Somashekar
In this study titanium (Ti4+) doped zinc oxide (ZnO) nanoparticles were synthesized via a green solution combustion method employing Calotropis gigantea as fuel. Employing various characterization techniques, the structural, morphological, elastic, and electromechanical properties were studied. The Rietveld refinement confirms the presence of hexagonal wurtzite structure with lattice strain induced by Ti4+ substitution. The computational simulation using GULP reveals how Ti4+ doping modifies the mechanical stiffness and dielectric response of ZnO by showing direction-dependent elastic and dielectric behaviour. The crystallite size obtained using Scherrer equation and dislocation density have shown a non-linear trend with optimal grain growth at 5 % of Ti4+ as observed in 3D map. Electron density (ED) mapping reveals evolving symmetry and strain distribution across doping levels. The analysis of surface texture highlights enhanced surface waviness and roughness with heterogeneity. The shift in vibrational modes can be seen in FTIR spectra, affirming dopant incorporation and reduced surface organics. A tunable bandgap from 3.25 to 3.50 eV have been obtained using UV–Vis absorption, showing potential for optoelectronics. These materials have application in UV-protective coatings, sensors, and photocatalytic systems.
{"title":"Structural, morphological, optical, and electromechanical analysis of green-synthesized Ti-doped ZnO nanoparticles for optoelectronic applications","authors":"V.V. Manju , R. Sanjana , Vinayakprasanna N. Hegde , S. Divakara , B.C. Hemaraju , Janya Lumbini , Namratha , N. Raghu , R. Somashekar","doi":"10.1016/j.micrna.2025.208537","DOIUrl":"10.1016/j.micrna.2025.208537","url":null,"abstract":"<div><div>In this study titanium (Ti<sup>4+</sup>) doped zinc oxide (ZnO) nanoparticles were synthesized via a green solution combustion method employing <em>Calotropis gigantea</em> as fuel. Employing various characterization techniques, the structural, morphological, elastic, and electromechanical properties were studied. The Rietveld refinement confirms the presence of hexagonal wurtzite structure with lattice strain induced by Ti<sup>4+</sup> substitution. The computational simulation using GULP reveals how Ti<sup>4+</sup> doping modifies the mechanical stiffness and dielectric response of ZnO by showing direction-dependent elastic and dielectric behaviour. The crystallite size obtained using Scherrer equation and dislocation density have shown a non-linear trend with optimal grain growth at 5 % of Ti<sup>4+</sup> as observed in 3D map. Electron density (ED) mapping reveals evolving symmetry and strain distribution across doping levels. The analysis of surface texture highlights enhanced surface waviness and roughness with heterogeneity. The shift in vibrational modes can be seen in FTIR spectra, affirming dopant incorporation and reduced surface organics. A tunable bandgap from 3.25 to 3.50 eV have been obtained using UV–Vis absorption, showing potential for optoelectronics. These materials have application in UV-protective coatings, sensors, and photocatalytic systems.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"211 ","pages":"Article 208537"},"PeriodicalIF":3.0,"publicationDate":"2025-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145884875","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}
InAs/AlSb superlattices have demonstrated great potential for developing mid-infrared optoelectronic devices, however, there has been a limited amount of research dedicated to investigating their interfaces. In this work, the interfaces of InAs/AlSb superlattices grown by molecular beam epitaxy are investigated by scanning transmission electron microscopy and electron energy loss spectroscopy. The results clearly identify residual Sb atoms in InAs sublayers and intermixing at the interfaces. First-principles calculations suggest that the incorporation of a limited amount of Sb into the InAs sublayers may facilitate strain balance without significantly affecting the band alignment of the InAs/AlSb superlattices. The intermixing interface offers a trade-off between AlAs- and InSb-type interfaces for achieving strain balance, and it has the potential to alter the electronic structure of the superlattices, particularly for samples with very short periods.
{"title":"Investigation on the interfacial effects of InAs/AlSb superlattices","authors":"Heping An , Rui Xu , Peng Wu , Wenyan Zhao , Chunhui Zhu , Lianqing Zhu","doi":"10.1016/j.micrna.2025.208536","DOIUrl":"10.1016/j.micrna.2025.208536","url":null,"abstract":"<div><div>InAs/AlSb superlattices have demonstrated great potential for developing mid-infrared optoelectronic devices, however, there has been a limited amount of research dedicated to investigating their interfaces. In this work, the interfaces of InAs/AlSb superlattices grown by molecular beam epitaxy are investigated by scanning transmission electron microscopy and electron energy loss spectroscopy. The results clearly identify residual Sb atoms in InAs sublayers and intermixing at the interfaces. First-principles calculations suggest that the incorporation of a limited amount of Sb into the InAs sublayers may facilitate strain balance without significantly affecting the band alignment of the InAs/AlSb superlattices. The intermixing interface offers a trade-off between AlAs- and InSb-type interfaces for achieving strain balance, and it has the potential to alter the electronic structure of the superlattices, particularly for samples with very short periods.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"211 ","pages":"Article 208536"},"PeriodicalIF":3.0,"publicationDate":"2025-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145841732","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 comprehensive investigation of thermoelectric transport properties in halogenated silicene XSi (X = F, Cl, Br, I) was conducted through first-principles calculations coupled with Boltzmann transport theory. The regulatory mechanisms of halogen doping on phonon scattering, electronic band structures, and thermoelectric figure of merit were systematically elucidated. Weak anisotropy in thermal transport characteristics was observed across halogenated silicene derivatives, with lattice thermal conductivities along the X-direction at room temperature being quantified as 5.46 W/(m·K) (FSi), 17.83 W/(m·K) (ClSi), 10.42 W/(m·K) (BrSi), and 1.50 W/(m·K) (ISi). Successful bandgap opening in monolayer silicene through halogenation was demonstrated by HSE06-calculated bandgap values ranging from 1.61 to 2.21 eV. Superior electronic transport performance was identified in FSi, exhibiting a maximum power factor (PF) of 356 μW/(m·K2) and achieving a peak n-type ZT value of 2.93 at 700 K, which was found to significantly exceed the maximum ZT values of 0.84 (ClSi), 1.32 (BrSi), and 0.73 (ISi) recorded for other derivatives. Halogenation is thereby established as an effective strategy for modulating thermoelectric performance in silicene-based systems, providing theoretical foundations for the design of silicon-based thermoelectric materials.
{"title":"Study on thermoelectric transport properties of halogenated silicene","authors":"Yuanchao Liu, Duan Li, Zishuo Li, Xinhao Liu, Bohan Li, Letao Chang","doi":"10.1016/j.micrna.2025.208533","DOIUrl":"10.1016/j.micrna.2025.208533","url":null,"abstract":"<div><div>A comprehensive investigation of thermoelectric transport properties in halogenated silicene XSi (X = F, Cl, Br, I) was conducted through first-principles calculations coupled with Boltzmann transport theory. The regulatory mechanisms of halogen doping on phonon scattering, electronic band structures, and thermoelectric figure of merit were systematically elucidated. Weak anisotropy in thermal transport characteristics was observed across halogenated silicene derivatives, with lattice thermal conductivities along the X-direction at room temperature being quantified as 5.46 W/(m·K) (FSi), 17.83 W/(m·K) (ClSi), 10.42 W/(m·K) (BrSi), and 1.50 W/(m·K) (ISi). Successful bandgap opening in monolayer silicene through halogenation was demonstrated by HSE06-calculated bandgap values ranging from 1.61 to 2.21 eV. Superior electronic transport performance was identified in FSi, exhibiting a maximum power factor (PF) of 356 μW/(m·K<sup>2</sup>) and achieving a peak n-type ZT value of 2.93 at 700 K, which was found to significantly exceed the maximum ZT values of 0.84 (ClSi), 1.32 (BrSi), and 0.73 (ISi) recorded for other derivatives. Halogenation is thereby established as an effective strategy for modulating thermoelectric performance in silicene-based systems, providing theoretical foundations for the design of silicon-based thermoelectric materials.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"211 ","pages":"Article 208533"},"PeriodicalIF":3.0,"publicationDate":"2025-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145841731","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 : 2025-12-19DOI: 10.1016/j.micrna.2025.208529
Yanfen Li , Kangchun Tan , Hongyu Wangcheng , Le Zhao , Shihui Yu
Transparent film heaters (TFHs) are essential for emerging wearable and skin‐attachable devices. However, ITO suffers from intrinsic brittleness, while pristine Ag nanowires (Ag NWs) exhibit poor adhesion and limited environmental stability. Herein, we report ultra-flexible Ni@Ag NW/poly (vinylidene fluoride) (PVDF) hybrid transparent conductive thin films fabricated via a facile transfer–electroplating strategy. Ag NWs are partially embedded in the PVDF matrix to ensure robust mechanical reinforcement, while conformal Ni nano-shells provide dense protection against oxidation and corrosive species without deterioration of transparency. The prepared films combine high optical transmittance (92 % at 550 nm), low sheet resistance (∼29 Ω/□), and remarkable mechanical durability, maintaining stable conductivity under a 0.5 mm bending radius for 1000 cycles and after 300 s ultrasonication tests. When applied as TFHs, the heaters deliver tunable steady-state temperatures up to ∼75 °C at 4 V, with ultrafast response (∼15 s), excellent cycling stability, and long-term thermal reliability. More importantly, Ni@Ag NW/PVDF hybrid films exhibit exceptional environmental robustness, resisting oxidation, chloride corrosion, and sulfidation under harsh accelerated aging and chemical immersion tests. This scalable strategy provides stable, high-performance electrodes for next-generation transparent optoelectronics and wearable devices.
{"title":"Ultraflexible and highly stable transparent heaters based on Ni@Ag nanowire/PVDF composites","authors":"Yanfen Li , Kangchun Tan , Hongyu Wangcheng , Le Zhao , Shihui Yu","doi":"10.1016/j.micrna.2025.208529","DOIUrl":"10.1016/j.micrna.2025.208529","url":null,"abstract":"<div><div>Transparent film heaters (TFHs) are essential for emerging wearable and skin‐attachable devices. However, ITO suffers from intrinsic brittleness, while pristine Ag nanowires (Ag NWs) exhibit poor adhesion and limited environmental stability. Herein, we report ultra-flexible Ni@Ag NW/poly (vinylidene fluoride) (PVDF) hybrid transparent conductive thin films fabricated via a facile transfer–electroplating strategy. Ag NWs are partially embedded in the PVDF matrix to ensure robust mechanical reinforcement, while conformal Ni nano-shells provide dense protection against oxidation and corrosive species without deterioration of transparency. The prepared films combine high optical transmittance (92 % at 550 nm), low sheet resistance (∼29 Ω/□), and remarkable mechanical durability, maintaining stable conductivity under a 0.5 mm bending radius for 1000 cycles and after 300 s ultrasonication tests. When applied as TFHs, the heaters deliver tunable steady-state temperatures up to ∼75 °C at 4 V, with ultrafast response (∼15 s), excellent cycling stability, and long-term thermal reliability. More importantly, Ni@Ag NW/PVDF hybrid films exhibit exceptional environmental robustness, resisting oxidation, chloride corrosion, and sulfidation under harsh accelerated aging and chemical immersion tests. This scalable strategy provides stable, high-performance electrodes for next-generation transparent optoelectronics and wearable devices.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"211 ","pages":"Article 208529"},"PeriodicalIF":3.0,"publicationDate":"2025-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145841728","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}
Monolayer gallium nitride (GaN) has emerged as a highly promising material for nanoelectronic and nanoelectromechanical systems (NEMS) due to its exceptional electronic, optical, and mechanical properties; however, its mechanical reliability is strongly affected by intrinsic lattice defects and polycrystalline microstructure, which are inevitable in experimentally synthesized films and critically undermine performance. In this work, large-scale classical molecular dynamics (MD) simulations are used to systematically investigate the tensile behavior and fracture mechanisms of monolayer GaN, focusing on the effects of grain size, point vacancies, strain rate, and temperature. Polycrystalline GaN exhibits a clear inverse pseudo–Hall–Petch trend, where both tensile strength and elastic modulus increase as the grain size increases from 2 to 35 nm. For the smallest grains, the tensile strength reaches only ∼24 % of that of pristine single-crystalline GaN because grain boundaries act as defect-rich stress concentrators and early crack-nucleation sites. Point vacancies further amplify mechanical degradation: the introduction of just 1 % vacancies reduces the elastic modulus and tensile strength by ∼18 % and ∼47 %, respectively, due to local lattice instability and stress localization. Ga vacancies create larger voids and pronounced lattice distortion, promoting premature bond rupture and a severe reduction in tensile strength, whereas N vacancies primarily decrease the elastic modulus as their higher charge density and stronger Ga–N ionic character weaken bond stiffness and increase lattice deformability. The deformation profiles, radial distribution function, and potential energy per atom are also calculated to support the interpretation of fracture properties. Temperature also significantly affects the mechanical response. As the temperature increases from 100 K to 700 K, the elastic modulus and tensile strength decrease by ∼4 % and ∼35 %, respectively, because enhanced atomic vibrations weaken bond stiffness and reduce the strain energy required for fracture. Pristine monolayer GaN further exhibits strong mechanical anisotropy: the armchair orientation shows higher strain-rate sensitivity due to direct bond stretching along the loading axis, while the zigzag direction accommodates deformation mainly through bond-angle adjustments, resulting in weaker rate dependence. These findings offer essential atomic-level insights that enhance the fundamental understanding and predictive design of mechanically resilient monolayer GaN, facilitating its reliable integration into next-generation nanoelectronic and NEMS applications.
{"title":"Atomistic insights into grain size and vacancy effects on the mechanical behavior of monolayer GaN","authors":"Arman Hossain , A.S.M. Jannatul Islam , Durjoy Sarkar Dhrubo , Md. Mehidi Hassan","doi":"10.1016/j.micrna.2025.208531","DOIUrl":"10.1016/j.micrna.2025.208531","url":null,"abstract":"<div><div>Monolayer gallium nitride (GaN) has emerged as a highly promising material for nanoelectronic and nanoelectromechanical systems (NEMS) due to its exceptional electronic, optical, and mechanical properties; however, its mechanical reliability is strongly affected by intrinsic lattice defects and polycrystalline microstructure, which are inevitable in experimentally synthesized films and critically undermine performance. In this work, large-scale classical molecular dynamics (MD) simulations are used to systematically investigate the tensile behavior and fracture mechanisms of monolayer GaN, focusing on the effects of grain size, point vacancies, strain rate, and temperature. Polycrystalline GaN exhibits a clear inverse pseudo–Hall–Petch trend, where both tensile strength and elastic modulus increase as the grain size increases from 2 to 35 nm. For the smallest grains, the tensile strength reaches only ∼24 % of that of pristine single-crystalline GaN because grain boundaries act as defect-rich stress concentrators and early crack-nucleation sites. Point vacancies further amplify mechanical degradation: the introduction of just 1 % vacancies reduces the elastic modulus and tensile strength by ∼18 % and ∼47 %, respectively, due to local lattice instability and stress localization. Ga vacancies create larger voids and pronounced lattice distortion, promoting premature bond rupture and a severe reduction in tensile strength, whereas N vacancies primarily decrease the elastic modulus as their higher charge density and stronger Ga–N ionic character weaken bond stiffness and increase lattice deformability. The deformation profiles, radial distribution function, and potential energy per atom are also calculated to support the interpretation of fracture properties. Temperature also significantly affects the mechanical response. As the temperature increases from 100 K to 700 K, the elastic modulus and tensile strength decrease by ∼4 % and ∼35 %, respectively, because enhanced atomic vibrations weaken bond stiffness and reduce the strain energy required for fracture. Pristine monolayer GaN further exhibits strong mechanical anisotropy: the armchair orientation shows higher strain-rate sensitivity due to direct bond stretching along the loading axis, while the zigzag direction accommodates deformation mainly through bond-angle adjustments, resulting in weaker rate dependence. These findings offer essential atomic-level insights that enhance the fundamental understanding and predictive design of mechanically resilient monolayer GaN, facilitating its reliable integration into next-generation nanoelectronic and NEMS applications.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"211 ","pages":"Article 208531"},"PeriodicalIF":3.0,"publicationDate":"2025-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145841733","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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