Micro and Nanostructures最新文献

{"title":"Dual peaks of optical absorption in MgZnO/AlGaN core-shell nanowires","authors":"Y.M. Tang,&nbsp;X.H. Ji,&nbsp;Y. Qu","doi":"10.1016/j.micrna.2025.208284","DOIUrl":"10.1016/j.micrna.2025.208284","url":null,"abstract":"<div><div>ZnO nanowire is one of the most promising candidates for ultraviolet optoelectric emitters and detectors which can be well prepared on Si substrates. However, the relatively poor p-type doping and high density of surface defects in ZnO nanowires seriously limits its inner quantum efficiency. A p-type wurtzite AlGaN shell of ZnO could be a solution by serving both as the holes provider and a barrier which keeps the surface defects away. In this work, optical absorption in MgZnO nanowires wrapped by a wurtzite AlGaN shell is investigated by Fermi golden rule with consideration of the wurtzite and rocksalt mixed crystal structure in MgZnO. The calculations show that the wurtzite AlN shell could provide a quantum confinement to carriers in MgZnO nanowire with large range of component. Furthermore, it is interesting to find that the mixed crystal phases in MgZnO leads to dual response frequencies of photons. The double optical absorption peaks from the inter band transition of electrons always can be recognized due to their large difference on frequencies. While the dual peaks from inter-subband transitions are tend to exhibit as a broadening especially in the nanowire with a high Mg mole fraction or a large radius. The results give a guidance for the MgZnO/AlGaN core-shell nanowires ultraviolet detectors with multi response frequency.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"207 ","pages":"Article 208284"},"PeriodicalIF":3.0,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144826832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficiency enhancement in perovskite solar cells through optimized MgF2 textured surface engineering: Light-management optimization","authors":"Vishal Yadav ,&nbsp;Rahul Pandey ,&nbsp;Jaya Madan","doi":"10.1016/j.micrna.2025.208283","DOIUrl":"10.1016/j.micrna.2025.208283","url":null,"abstract":"<div><div>Optimal light management in perovskite solar cells (PSCs) is very crucial to increase the photon absorption and overall performance of the device. In the present study, an MgF₂ textured front surface has been applied to the PSCs followed by the optimization of different parameters including pyramid angle (54°–55°), offset (0–1 μm), and refractive index of textured surface (1.4–2.0). The presence of a textured surface with optimized parameters of pyramid angle (54.4°), offset (0 μm), and reflective index (1.4) resulted in an enhanced photogeneration rate and short circuit current density (J_SC) 26.24 mA cm⁻² with remaining photovoltaic (PV) parameters: open circuit voltage (V_OC) 1.228 V, fill factor (FF) 77.86 % and power conversion efficiency (PCE) 25.10 %. All the PSC devices are analyzed with the help of the current density voltage curve (J-V), external quantum efficiency (EQE), photogeneration rate, and optical intensity profile within the device structure. The proposed front surface design may pave the way for the efficient utilization of optical spectrum and for the development of advanced high-efficiency PSC.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"207 ","pages":"Article 208283"},"PeriodicalIF":3.0,"publicationDate":"2025-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144770779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simulation on a field-stop IGBT with inversion-channel metal-oxide-semiconductor system and Si/4H–SiC hetero-junction emitter","authors":"Zisheng Wang ,&nbsp;Wensheng Wei ,&nbsp;Zhizhan Ye ,&nbsp;Jintian Yang","doi":"10.1016/j.micrna.2025.208280","DOIUrl":"10.1016/j.micrna.2025.208280","url":null,"abstract":"<div><div>A field-stop IGBT including n-type and p-type channel metal-oxide-semiconductor (MOS) systems and Si/4H–SiC hetero-junction emitter (HEJE) is proposed. The n-MOS aside the primary gate is adopted to conduct electrons for realizing the enhanced device, the <em>p</em>-MOS aside the auxiliary gate is employed to extract holes during turn-off for decreasing energy loss (<em>E</em>_off). The HEJE acts as potential barrier to hinder holes outflow for enhancing conductance modulation while reducing on-state voltage (<em>V</em>_on) without falling breakdown voltage (<em>V</em>_B). The device structure and performance are simulated and optimized by the Sentaurus TCAD, the operation mechanism is elucidated, the influence from the interfacial defects in Si/4H-SiC HEJE, p-MOS and n-MOS on device performance is analyzed respectively. The devised IGBT shows obvious decrease in <em>V</em>_on and <em>E</em>_off comparing to the counterparts without HEJE and p-MOS. This paper provides new scheme for designing superior IGBT.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"207 ","pages":"Article 208280"},"PeriodicalIF":3.0,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144886663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhanced VOC sensing performance of MWCNT-CuO/ZnO nanocomposite based vertical TFET","authors":"Abdulrahman Saad Alqahtani ,&nbsp;Hashim Elshafie ,&nbsp;Azath Mubarakali ,&nbsp;M. Suresh Chinnathampy ,&nbsp;A. Alavudeen Basha ,&nbsp;P. Parthasarathy ,&nbsp;M. Venkatesh","doi":"10.1016/j.micrna.2025.208281","DOIUrl":"10.1016/j.micrna.2025.208281","url":null,"abstract":"<div><div>This study proposes a high-performance vertical tunnel field-effect transistor (VTFET)-based gas sensor incorporating a nanocomposite channel of multi-walled carbon nanotubes (MWCNTs) combined with CuO/ZnO bilayers. The design leverages the enhanced surface area, superior carrier transport, and strong gate coupling enabled by the vertical configuration to significantly improve gas detection sensitivity. The sensing mechanism is based on modulation of the drain current due to variations in the gate metal's work function upon exposure to volatile organic compounds (VOCs). These changes alter the surface potential and tunneling barrier, producing detectable shifts in the electrical characteristics without relying solely on threshold voltage modulation. Among the analytes examined, ethanol exhibited the highest sensitivity, with a 2.61 % increase in ON-current for a gate work function shift from 45 meV to 200 meV, followed by methanol (2.32 %) and acetone (2.12 %). The sensor achieves a steep subthreshold swing and an exceptionally high I_ON/I_OFF ratio of ∼10¹², indicating excellent switching behaviour and ultra-low leakage. It operates with a maximum threshold voltage of 0.8 V for ethanol detection and maintains low power consumption due to its efficient band-to-band tunneling process. The use of CMOS-compatible materials such as HfO₂, CuO, ZnO, and MWCNTs supports scalable fabrication and cost efficiency. These features make the proposed sensor a strong candidate for real-time VOC detection in various domains, including environmental monitoring, industrial safety, biomedical diagnostics, and automotive applications.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"207 ","pages":"Article 208281"},"PeriodicalIF":3.0,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144750246","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of temperature and defects on microstructure and mechanical properties of nano-silica/C–S–H composites","authors":"Jianlin He ,&nbsp;Chunwei Zhang ,&nbsp;Guili Liu","doi":"10.1016/j.micrna.2025.208278","DOIUrl":"10.1016/j.micrna.2025.208278","url":null,"abstract":"<div><div>Calcium silicate hydrate (C–S–H) is a primary source of concrete strength, and optimizing its properties is crucial for enhancing the durability of concrete. Nanosilica (NS) as a reinforcing phase can effectively improve the C–S–H properties; however, its actual efficacy is significantly affected by the service temperature and its defects, and the coupling mechanism between the two at the atomic scale remains unclear. In this study, molecular dynamics simulations were employed to systematically elucidate the mechanism of the synergistic effects of temperature (100 K–500 K) and three typical oxygen defects (V1, V2, and V3) on the interfacial structure and mechanical properties of NS/C–S–H composites. The results indicate that oxygen defects enhance the interaction of NS with water molecules, thereby increasing the material's hydrophilicity to a certain extent. However, this hydrophilicity gradually decreases with increasing temperature, especially at 400K and 500K. The radial distribution function (RDF) analysis reveals that an increase in temperature results in a decrease in the characteristic peaks of Oz-Ow and Si–Os, indicating that the interatomic distances have increased and the interactions have weakened. At 300 K, the tensile strength (1.590 GPa) and Young's modulus (30.872 GPa) of the NS/C–S–H composites were greater compared to those of the C–S–H gels. NS-V2 exhibits the highest tensile strength (1.773 GPa) at 300K. NS-V3, on the other hand, exhibits excellent tensile toughness and compression modulus in the 100K–200K and 400K–500K ranges. In contrast, NS-V1 has limited mechanical property enhancement. This study elucidates the mechanism of the multivariate coupling effect of temperature and oxygen defects on NS/C–S–H at the atomic scale. The findings provide a basis for optimizing the strength, modulus, and toughness of composites at different service temperatures (especially at medium and high temperatures), which is essential for the design of high-performance concretes for applications in extreme environments.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"207 ","pages":"Article 208278"},"PeriodicalIF":3.0,"publicationDate":"2025-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144739749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Goos–Hänchen shift in a one-dimensional dual-cavity photonic crystal containing graphene and Weyl semimetal","authors":"Akram Ashenaei ,&nbsp;Kazem Jamshidi-Ghaleh ,&nbsp;Reza Abdi-Ghaleh","doi":"10.1016/j.micrna.2025.208279","DOIUrl":"10.1016/j.micrna.2025.208279","url":null,"abstract":"<div><div>This paper investigates the Goos–Hänchen (GH) shift in a one-dimensional photonic crystal (1DPC) structure with a dual-cavity configuration. It consists of two photonic micro-cavities, with arrangement of <span><math><mrow><msup><mrow><mo>(</mo><mtext>AB</mtext><mo>)</mo></mrow><mi>N</mi></msup><mi>G</mi><mspace></mspace><msup><mrow><mo>(</mo><mtext>BA</mtext><mo>)</mo></mrow><mi>M</mi></msup><mi>B</mi><mspace></mspace><mi>C</mi><mspace></mspace><msup><mrow><mo>(</mo><mtext>BA</mtext><mo>)</mo></mrow><mi>N</mi></msup></mrow></math></span>, one is designed with a Weyl semimetal (C) layer and the other one with a graphene (G), where A and B are dielectric layers. The reflection spectrum of an incident wave with TM polarization, its relative phase and the corresponding GH shift are calculated using the 2 × 2 transfer matrix method. The results indicate that the proposed structure exhibits two defect modes at a frequency of 235 THz (λ <span><math><mrow><mo>=</mo><mn>8.01</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span>), occurring at angles of 18.7 and 53.9°, which lead to GH shifts of +37.8 λ and −4.9 λ, respectively. The effect of the G and C relative position, the chemical potential of graphene, the Fermi energy and the distance between Weyl nodes have examined for controlling the GH shift. This high tunability makes the proposed structure suitable for designing controllable optical devices and highly sensitive sensors based on the GH shift.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"207 ","pages":"Article 208279"},"PeriodicalIF":3.0,"publicationDate":"2025-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144770778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tailoring of the transfer characteristics of nanowire-based GAA-FETs through the channel defects and its effect on the energy-current spectrum","authors":"Aruna Gupta,&nbsp;Niladri Sarkar","doi":"10.1016/j.micrna.2025.208277","DOIUrl":"10.1016/j.micrna.2025.208277","url":null,"abstract":"<div><div>Studies are performed to investigate the effect of channel defects on the transfer and output characteristics of Nanowire-GAA-FETs. It is observed that the transfer characteristics can be tuned by invoking defect-induced scattering potential in the nanowire channel. Here, the channel scattering potentials chosen are step-shaped and pulse-shaped. The effect of such potentials on the energy-current spectrum of the nanowire device is also studied. It is observed that the normalized energy-current spectrum shrinks due to scattering potential. This results in the early triggering of the device saturation. Also, it is observed that the energy-current spectrum gets enhanced as the gate voltage of the device is increased. This signifies the role of channel currents of different energies in the transport mechanism. Here, the effect of channel defects on device saturation current is corroborated with the corresponding impact on the energy-current spectrum of the nanowire device. This work explains the implication of the modified energy-current spectrum under defect-induced scattering potentials and its effect on the device transfer characteristics. Hence, this idea can be extended to tailor the transfer characteristics through intentionally and unintentionally invoked channel defects on low-dimensional FETs. Also, we have studied the effect of defects on the transconductance, threshold voltage and the subthreshold swing of nanowires FETs. Here, we compared the simulated results with the experimental results of a real GAA-based biosensor.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"207 ","pages":"Article 208277"},"PeriodicalIF":3.0,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144763944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Elastic modulus, ultimate stress, and toughness of pop-graphene nanotubes: A detailed analysis of structural and environmental factors","authors":"Shengju Tang ,&nbsp;Zhang Pan ,&nbsp;Li-Cai Zhao","doi":"10.1016/j.micrna.2025.208276","DOIUrl":"10.1016/j.micrna.2025.208276","url":null,"abstract":"<div><div>This study investigates the mechanical properties and fracture behavior of pop-graphene nanotubes through molecular dynamics simulations, focusing on the influence of structural parameters such as length, diameter, chirality, and the number of walls, as well as external factors like temperature and defects. Theoretical results indicate that armchair-oriented nanotubes exhibit ductile-like deformation due to their perpendicular bond arrangement, while zigzag-oriented nanotubes display brittle fracture behavior owing to their angled bond alignment. Quantitative analysis reveals that for the armchair configuration, the ultimate stress decreases by 34.7 % (from 1068.3 GPa to 697.7 GPa) as the length increases from 50 Å to 150 Å, whereas the zigzag configuration shows a 25.7 % decrease (from 791.5 GPa to 588.4 GPa) over the same range. Additionally, increasing the diameter leads to a 19.05 % increase in ultimate stress for armchair nanotubes and a 20.52 % increase for zigzag nanotubes, highlighting a distinct size-dependent strengthening effect. Thermal softening significantly degrades mechanical performance, with the elastic modulus decreasing by 56.2 % for armchair and 61.6 % for zigzag nanotubes as temperature rises from 200 K to 1000 K. Furthermore, multi-walled structures show reduced strength, with the ultimate stress declining by 17.4 % for armchair and 16.5 % for zigzag configurations as the number of walls increases from 1 to 5. These findings underscore the anisotropic mechanical response of pop-graphene nanotubes, driven by their distinct atomic arrangements and bond orientations. This work provides critical insights into the design and optimization of pop-graphene nanotubes for applications requiring tailored mechanical properties in fields such as nanocomposites, nanoelectromechanical systems, and high-performance structural materials.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"207 ","pages":"Article 208276"},"PeriodicalIF":3.0,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144766927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigating the effects of heavy-ion radiation on n-type Step Tunnelling Path TFET","authors":"Jatismar Saha ,&nbsp;Manosh Protim Gogoi ,&nbsp;Shreyas Tiwari ,&nbsp;Bijit Choudhuri ,&nbsp;Rajesh Saha","doi":"10.1016/j.micrna.2025.208269","DOIUrl":"10.1016/j.micrna.2025.208269","url":null,"abstract":"<div><div>This study investigates the impact of heavy-ion radiation on Step Tunneling Path (STP) TFET, focusing on charge deposition, device stability, and performance in radiation-intensive environments. Using Sentaurus TCAD simulations, the effects of heavy-ion generation are analysed at specific locations within the device 50, 100, 150, 200, and 230 nm from the source region. The analysis reveals that at linear energy transfer (LET) = 50 MeV-cm²/mg, the drain current (I_D) reaches approximately 28,000 μA, demonstrating a significant transient response due to increased charge deposition. The study also examines the effect of varying ion incidence angles (0°, 30°, 45°, 60°, and 90°) at constant LET of 20 MeV-cm²/mg. Results indicate that at 0° incidence angle, the drain current peaks at approximately 200,000 μA, emphasizing the critical role of impact geometry in radiation-induced device degradation. The findings confirm that heavy ions deposit more charge along their trajectory compared to alpha particles, leading to higher ionization densities and stronger transient effects. This research provides crucial insights into the radiation resilience of STP-TFETs, making them viable candidates for high-energy and space applications.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"207 ","pages":"Article 208269"},"PeriodicalIF":2.7,"publicationDate":"2025-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144680522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sensitivity of resonant tunneling diodes to barrier variation and quantum well variation: A NEGF study","authors":"Pranav Acharya,&nbsp;Naveen Kumar,&nbsp;Ankit Dixit,&nbsp;Vihar Georgiev","doi":"10.1016/j.micrna.2025.208264","DOIUrl":"10.1016/j.micrna.2025.208264","url":null,"abstract":"<div><div>A Non-Equilibrium Green’s Function (NEGF) simulation study on the impact of varying barriers and quantum well (QW) for a double barrier GaAs/Al<span><math><msub><mrow></mrow><mrow><mtext>0.3</mtext></mrow></msub></math></span>Ga<span><math><msub><mrow></mrow><mrow><mtext>0.7</mtext></mrow></msub></math></span>As Resonant Tunneling Diode (RTD) was carried out. This includes both variation of section thicknesses and the inclusion of interface roughness (IR) at different GaAs/Al<span><math><msub><mrow></mrow><mrow><mtext>0.3</mtext></mrow></msub></math></span>Ga<span><math><msub><mrow></mrow><mrow><mtext>0.7</mtext></mrow></msub></math></span>As interfaces. Narrower QWs and thinner symmetric barriers both resulted in a perturbation of Negative Differential Region (NDR) of the current–voltage (I-V) characteristic to greater bias. Asymmetric variation of the barriers controlled the perturbation of the resonant peak bias <span><math><msub><mrow><mi>V</mi></mrow><mrow><mi>r</mi></mrow></msub></math></span>, with a thinner first barrier resulting in a perturbation to greater bias and a thinner second barrier resulting in the inverse. Both barrier thicknesses inversely impacted the current, with the first barrier having a greater impact. The impact of IR was studied using the average of 25 device I-V characteristics for a given configuration of IR, as well as the I-V characteristic and charge density of specific devices. It was found that IR along the QW reduced the effective QW width and IR along the barriers increased their effective thickness, which together explained the effects of IR along all Al<span><math><msub><mrow></mrow><mrow><mtext>0.3</mtext></mrow></msub></math></span>Ga<span><math><msub><mrow></mrow><mrow><mtext>0.7</mtext></mrow></msub></math></span>As interfaces.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"207 ","pages":"Article 208264"},"PeriodicalIF":2.7,"publicationDate":"2025-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144686209","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}