Micro and Nanostructures最新文献

{"title":"Effect of oxygen in the annealing treatment of Al2O3/β-Ga2O3 MOS capacitors","authors":"Yuxiang Lin ,&nbsp;Song Du ,&nbsp;Hao Long","doi":"10.1016/j.micrna.2025.208321","DOIUrl":"10.1016/j.micrna.2025.208321","url":null,"abstract":"<div><div>Gallium oxide (Ga₂O₃) has emerged as a highly promising material for high-power electronic applications, owing to its ultra-wide bandgap, exceptional breakdown electric field, and low conduction losses. However, interfacial defects between Ga₂O₃ and the gate dielectric critically undermine device performance, highlighting the urgent need for robust interface engineering strategies. This study investigated the effect of annealing treatment on the interfacial and dielectric properties of Al₂O₃/β-Ga₂O₃ metal-oxide-semiconductor (MOS) capacitors. A comprehensive analysis of interface, border, and bulk traps revealed that O₂ annealing markedly improved both interface passivation and dielectric properties. The presence of active oxygen species promoted Ga–O bond formation, suppressing surface dangling bonds and oxygen vacancies, and thereby enabling the growth of a high-quality dielectric layer. In contrast, while N₂ annealing reduced surface contaminants, its lack of active oxygen species limited defect passivation. These results underscored the pivotal role of oxygen in thermal treatments and offered a practical route toward high-performance Ga₂O₃-based power devices.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"208 ","pages":"Article 208321"},"PeriodicalIF":3.0,"publicationDate":"2025-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144926557","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":"Neuromorphic integration and real-time programmability of temporally-coded phase-change plasmonic platforms for on-chip multilevel optical memory and adaptive logic systems","authors":"Viyat Varun Updhay ,&nbsp;N. Nagabhooshanam ,&nbsp;Sharad Rathore ,&nbsp;Madan Lal ,&nbsp;A.C. Santha Sheela ,&nbsp;D. Beulah ,&nbsp;A. Rajaram","doi":"10.1016/j.micrna.2025.208317","DOIUrl":"10.1016/j.micrna.2025.208317","url":null,"abstract":"<div><div>This research reports the operation, architecture of a neuromorphic-compatible and real-time, programmable optical memory device, through temporally encoded femtosecond laser excitation of phase-change plasmonic nanomaterials. High-quality Ge₂Sb₂Te₅ (GST) thin films with sub-nanometer roughness (0.46–0.61 nm) were fabricated over rigid substrates using RF-magnetron sputtering that provided a smooth phase transition. Bowtie antennas produced under electron beam lithography showed a local maximum electric field enhancement of |E/E₀| ≈ 18.2, with resonance peaks at wavelengths of ∼1270 nm. The amorphous, partially crystalline, and crystalline state transitions using a femtosecond laser, leading to reflectance modulations of 8.5–35.2 percent, were used to achieve 2-bit memory encoding (00–11) on a stable basis. Electrical characterization showed single-crystal conductivity deviations of more than four orders between the states, with switching times less than 180 ps measured by pump-probe. The finite-Difference Time-Domain (FDTD) and COMSOL simulations verified the photothermal triggered efficient activation and interface-limited crystallization with an Avrami exponent of ∼2.0 and the thermal hotspot temperature of ∼465 K. The write/erase drift was less than 5 percent at over 10,000 write/erase cycles, and optical logic gates (AND, OR, XOR) success rates of 97–100 percent were obtained. This system integrates memory and logic on one nanoscale platform and is reconfigurable, high-density, ultrafast, and low-power, with potential scalability to in-memory photonic computing and neuromorphic applications.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"208 ","pages":"Article 208317"},"PeriodicalIF":3.0,"publicationDate":"2025-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145020181","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 gold nanoparticles on resistive type nickel oxide based MEMS gas sensor properties","authors":"Аnastasia Kondrateva ,&nbsp;Ivan Komarevtsev ,&nbsp;Ilya Lazdin ,&nbsp;Yakov Enns ,&nbsp;Alexey Kazakin ,&nbsp;Elizaveta Fedorenko ,&nbsp;Alexandr Shakhmin ,&nbsp;Valentina Andreeva ,&nbsp;Maxim Mishin ,&nbsp;Platon Karaseov","doi":"10.1016/j.micrna.2025.208318","DOIUrl":"10.1016/j.micrna.2025.208318","url":null,"abstract":"<div><div>The technology to produce hydrogen sulphide sensor with a sensitive layer based on nickel oxide on a silicon chip is presented. Response of the sensor to H₂S in concentrations from 1 to 70 ppm at 190 °C operating temperature is investigated. Modification of NiO film with gold nanoparticles (GNPs) significantly improves sensitivity level. The sensing layer made of NiO embedded with GNPs shows five times higher response and improved response time compared to pure nickel oxide one. The response time under 70 ppm H₂S in Ar exposure is ∼5 s and the recovery time is ∼28 min. The enhanced sensitivity of NiO embedded with GNPs is attributed to (i) the increased crystallinity of NiO grown over the gold nanoparticles and (ii) the spillover effect of GNPs in NiO. MEMS technology used to produce the sensor chip with thin active layers makes it possible to drastically reduce the energy consumption of the sensor.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"207 ","pages":"Article 208318"},"PeriodicalIF":3.0,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144932085","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":"Advanced computational modeling and performance optimization of 3D/3D bilayer perovskite heterojunction in monolithic tandem photovoltaic device","authors":"Bhupender Singh ,&nbsp;Surender Kumar ,&nbsp;Jaspinder Kaur ,&nbsp;Rikmantra Basu ,&nbsp;Ajay Kumar Sharma ,&nbsp;Rahul Pandey ,&nbsp;Jaya Madan","doi":"10.1016/j.micrna.2025.208319","DOIUrl":"10.1016/j.micrna.2025.208319","url":null,"abstract":"<div><div>All-Perovskite tandem solar cells can generate high efficiency with long-term stability at low cost. Metal halide perovskite photovoltaic devices designed with tandem architectures could potentially enhance the efficiency of commercial single-junction solar cells from ∼20 % to ∼30 %. This work presents the design of an all-perovskite tandem solar cell of high efficiency made of perovskite absorber FA_0.8Cs_0.2Pb(I_0.6Br_0.4)₃ of 1.77 eV energy bandgap in the top cell and FA_0.7MA_0.3Pb_0.5Sn_0.5I₃ of 1.25 eV energy bandgap in the bottom cell. The narrow bandgap perovskite bottom sub-cell is designed with 3D/3D bilayer perovskite heterojunction between the perovskite absorber layer and electron transport layer to decrease interfacial non-radiative recombination. The standalone solar cell designs are optimized by refining parameters such as thickness, shallow donor/acceptor densities, bulk and interfacial trap densities, etc. These optimized designs are consequently integrated to design a tandem solar cell at current matching conditions and a comprehensive analysis of the designs is done. The designed tandem solar cell has a high efficiency of 30.8 % with short-circuit current density (J_SC) of 15.9 mA/cm², open-circuit voltage (V_OC) of 2.25 V, and high fill factor (FF) of 86 %. This simulated design contributes valuable insights for the development of tandem solar cells, supported by comparisons with prior experimental and computational results. The effect of Radiative recombination, Auger Recombination, series resistance and shunt resistance is also analyzed.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"207 ","pages":"Article 208319"},"PeriodicalIF":3.0,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144925404","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":"Analysis and performance improvement of short channel effects in MoSe2/WSe2 heterostructure MOSFETs","authors":"U. Malu ,&nbsp;J. Charles Pravin ,&nbsp;B. Veerasamy ,&nbsp;T.S. Arun Samuel","doi":"10.1016/j.micrna.2025.208308","DOIUrl":"10.1016/j.micrna.2025.208308","url":null,"abstract":"<div><div>As MOSFET miniaturization reaches physical limits, this work explores advancements to address scaling challenges. This work proposes hafnium dioxide (HfO₂) as a high-k gate dielectric for thinner layers and reduced power consumption. Additionally, SiO₂ spacers are investigated to address reliability concerns with air spacers in MOSFETs. Finally, to combat short channel effects that plague traditional materials like silicon, this research explores MoSe₂/WSe₂ Transition Metal Dichalcogenide (TMD) heterostructures due to their unique properties, aiming to contribute to MOSFET design advancements by mitigating these effects and enhancing overall device performance and reliability. The MOSFET is designed and simulated in TCAD Silvaco and achieves a SS of 57 mV/dec and a DIBL of 58 mV/V, demonstrating effective mitigation of short-channel effects.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"207 ","pages":"Article 208308"},"PeriodicalIF":3.0,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144906950","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":"LiTiAlO4: A novel wide band gap semiconductor for optoelectronic and thermal management, insight from DFT and AIMD within HSE06","authors":"Botan Jawdat Abdullah ,&nbsp;Nzar Rauf Abdullah","doi":"10.1016/j.micrna.2025.208312","DOIUrl":"10.1016/j.micrna.2025.208312","url":null,"abstract":"<div><div>LiTiAlO<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span> has a unique crystalline structure and combines lithium with transition metals. This study investigates the electronic structural, dynamic, thermal, and optical properties of LiTiAlO<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span> using advanced computational methods, including Density Functional Theory (DFT) with the HSE06 hybrid functional and Ab Initio Molecular Dynamics (AIMD). The material is very stable structurally, as shown by its negative formation energy of -3.226 eV and stable lattice parameters (<span><math><mrow><mi>a</mi><mo>=</mo><mn>5</mn><mo>.</mo><mn>76</mn></mrow></math></span> <span><math><mtext>Å</mtext></math></span>, <span><math><mrow><mi>b</mi><mo>=</mo><mn>5</mn><mo>.</mo><mn>92</mn></mrow></math></span> <span><math><mtext>Å</mtext></math></span>). The phonon dispersion analysis indicates that the material is stable over time, with no imaginary frequencies and a clear difference between the acoustic and optical phonon modes. The structure’s mechanical stability is confirmed according to fundamental elasticity theory. The phonon PDOS shows that oxygen dominates mid- and high-frequency modes, while lithium contributes at mid frequencies. These vibrations govern the temperature-dependent increase in heat capacity and decrease in thermal conductivity of LiTiAlO<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>. The low thermal conductivity is due to the enhanced phonon scattering rate within the structure, resulting from pronounced anharmonicity. The electronic band structure shows that it is a direct semiconductor with a wide bandgap of 4.82 eV (HSE06), which makes LiTiAlO<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span> a viable choice for ultraviolet (UV) optoelectronic uses. Its optical properties, such as its dielectric function, refractive index, absorption coefficient, and optical conductivity, show how well it can absorb light and create charge carriers. These findings collectively underscore LiTiAlO<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>’s suitability for advanced applications in optoelectronics, thermal management, and energy conversion technologies.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"207 ","pages":"Article 208312"},"PeriodicalIF":3.0,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144907021","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":"Linearity analysis of GNR TFETs with pocket engineering for high-performance RFIC applications","authors":"Md Akram Ahmad","doi":"10.1016/j.micrna.2025.208315","DOIUrl":"10.1016/j.micrna.2025.208315","url":null,"abstract":"<div><div>This work presents a comprehensive analysis of the linearity characteristics of graphene nanoribbon tunnel field-effect transistors (GNR TFETs) with source-end pocket engineering, emphasizing their suitability for advanced radio-frequency integrated circuit (RFIC) applications. The novelty of this study lies in the systematic optimization of the source pocket length and its quantified impact on key linearity figures of merit, including higher-order transconductance coefficients (<em>g</em>_<em>m2</em>, <em>g</em>_<em>m3</em>), second- and third-order intercept points (VIP2, IIP3), 1-dB compression point (1-dB CP), and harmonic distortion metrics (HD2, HD3). Atomistic simulations based on the Non-Equilibrium Green's Function (NEGF) formalism using NanoTCAD ViDES reveal that a 5 nm source pocket significantly enhances linearity by suppressing nonlinear components, improving signal integrity, and reducing intermodulation distortion. Benchmarking against state-of-the-art TFETs confirms the superior performance of the proposed structure, establishing it as a strong candidate for high-linearity, energy-efficient RFIC applications.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"207 ","pages":"Article 208315"},"PeriodicalIF":3.0,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144903976","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":"All-optical tunable transmittance in a 1D nonlinear ternary photonic crystal with graphene-oxide nanofilms","authors":"Shamsieh Hosseini Largani,&nbsp;Arezou Rashidi","doi":"10.1016/j.micrna.2025.208316","DOIUrl":"10.1016/j.micrna.2025.208316","url":null,"abstract":"<div><div>— In this paper, we investigate the dynamic tunability of light transmittance in a one-dimensional photonic crystal incorporating nonlinear (NL) Kerr nanofilms of graphene-oxide, focusing on the telecom wavelengths. The linear transmittance spectra reveal the existence of perfect transmittance resonance (PTR) at an incident wavelength of 1540 nm, with maximum electric field enhancement of approximately 11.2, resulting from the interaction between the incident light and the photonic bandgap of the structure. Once the high-intensity continuous-wave pump laser is normally incident on the structure, the linear PTR is reduced, accompanied by a decrease in field enhancement. Notably, as the intensity rises, the transmittance peak wavelength is red-shifted about 5 nm per 100 MW/cm² of input intensity, accompanied by strong resonance bending and the enhancement of weak off-resonance linear transmittance, due to the NL Kerr effect. Moreover, we observe S-shaped bistable transmittance behavior when the structure is excited at off-resonance wavelengths of 1545 nm and 1548 nm. At 1545 nm, the maximum bistability contrast is approximately 0.86 near an input intensity of 100 MW/cm², while at 1548 nm, it reaches about 0.95 near 157 MW/cm². These findings can provide a suitable platform for designing intensity-dependent optical switches and bistable optical devices within the telecommunication wavelength region.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"207 ","pages":"Article 208316"},"PeriodicalIF":3.0,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144907019","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":"Dielectric matrix-driven nonlinear optical response in cylindrical core–shell quantum dots: A theoretical insight","authors":"A. Naifar ,&nbsp;K. Hasanirokh ,&nbsp;A. Amouri ,&nbsp;W. Hayder","doi":"10.1016/j.micrna.2025.208314","DOIUrl":"10.1016/j.micrna.2025.208314","url":null,"abstract":"<div><div>Using the effective mass approximation and density matrix formalism, we develop a numerical model that incorporates self-polarization and bandgap discontinuity at the CdSe/ZnS cylindrical core-shell quantum dot/oxide interface. We quantitatively analyze the effects of core-to-shell radius ratio, quantum dot height and oxide permittivity on transition energies, electronic wavefunctions, oscillator strength, dipole matrix elements, and third-harmonic generation (THG) spectra. Our results reveal that surrounding oxide layers introduce additional confinement, modifying the electron energy spectrum. For a fixed shell radius R_S = 4.0 nm, the oscillator strength decreases, exhibiting a minimum near core radii R_C = 2.0 nm and 2.3 nm for HfO₂ and SiO₂, respectively. Under constant geometric conditions, the dipole matrix elements exhibit a pronounced increase with higher surrounding dielectric permittivity. In a dielectrically inhomogeneous environments, oxidation with HfO₂ (SiO₂) induces red (blue) shifts in resonance frequencies, coupled with stronger (weaker) amplitude modulation of THG peaks. These findings underscore the critical role of spatial confinement and dielectric effects in shaping the optical response of coated or solvent-dispersed nanostructures.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"207 ","pages":"Article 208314"},"PeriodicalIF":3.0,"publicationDate":"2025-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144907020","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":"High rectification efficiency Gate-All-Around Nanosheet and Nanowire nFETs for 2.45 GHz weak energy density microwave wireless power transmission","authors":"Huateng Li,&nbsp;Jianjun Song,&nbsp;Yuchen Zhang,&nbsp;Yue Wu,&nbsp;Congyang Huang","doi":"10.1016/j.micrna.2025.208313","DOIUrl":"10.1016/j.micrna.2025.208313","url":null,"abstract":"<div><div>The 2.45 GHz microwave signals in the environment can be collected by the microwave wireless power transmission system for applications. However, microwave signals in the 2.45 GHz band are in the weak energy density region, and receiver circuits with ordinary Si-based MOSFET as the rectifier device have low rectification efficiency. Therefore, based on Sentaurus TCAD simulation software, this paper designs and optimizes low-threshold-voltage Gate-All-Around (GAA) Nanosheet nFET and Gate-All-Around (GAA) Nanowire nFET models, taking advantage of the common-gate-stacking of GAA devices to achieve high drive current, low reverse leakage current, and low subthreshold swing. Finally, a half-wave rectifier circuit with a 0.1 pF filter capacitor and a 20 kΩ load resistor is constructed using the mixed-mode module of Sentaurus TCAD to validate the rectification performance of the two devices. At an input energy density of −10 dBm, the GAA Nanowire nFET achieves a rectification efficiency of 19.745 %, followed by the GAA Nanosheet nFET at 18.092 % and the Si-based nMOSFET at 10.942 %. At an input energy density of −15 dBm, the rectification efficiency drops to 9.806 %, 8.514 %, and 5.041 % for the GAA Nanowire nFET, the GAA Nanosheet nFET, and Si-based nMOSFET, respectively. These results confirm the superiority of GAA architectures in 2.45 GHz weak energy density microwave rectification, with the Nanowire variant consistently outperforming the Nanosheet counterpart by a small margin.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"207 ","pages":"Article 208313"},"PeriodicalIF":3.0,"publicationDate":"2025-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144892098","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}