Micro and Nanostructures最新文献

Effect of magnetic behavior of ZnO-based diluted magnetic semiconductors processed through TVA technique on room temperature CH3–CO–CH3 sensing properties TVA法制备zno基稀磁半导体的磁性行为对室温CH3-CO-CH3传感性能的影响

IF 3 Q2 PHYSICS, CONDENSED MATTER

Micro and Nanostructures

Pub Date : 2026-01-31 DOI: 10.1016/j.micrna.2026.208585

Nirlipta Kar, Sushanta Kumar Kamilla

The detection of hazardous volatile organic compounds such as acetone (CH₃–CO–CH₃), a highly flammable and widely used industrial solvent, is still a challenge at low temperature with fast response and recovery time. This study examines the impact of magnetic behaviour of Ni and Co doped ZnO (NZO and CZO) on the acetone sensing properties at room temperature (RT) processed by using thermo-vibrational annealing and vibrational dry-quenching (TVA) technique. Comparative analysis reveals that NZO processed through TVA exhibits better ferromagnetic behaviour and enhanced gas sensing performance compared to CZO, despite both having similarly reduced grain sizes. When exposed to 10 ppm of acetone at RT, NZO demonstrated higher sensitivity than CZO. Notably, NZO and CZO pellets processed via TVA shows higher sensitivity and shorter response/recovery time at RT over conventionally annealed counterparts. This sensor of NZO processed with TVA is found to have ∼37 % of sensitivity with fast response time of ∼23 s at RT. A strong correlation is observed between gas sensitivity and the squareness ratio of the magnetic hysteresis, highlighting the significant role of magnetic characteristics in gas sensing behavior. The temperature versus sensing behaviour indicates that the acetone response in Ni-doped ZnO is governed by coupled magneto-electronic interactions near the Curie temperature. Additionally, photoluminescence analysis reveals an increased oxygen vacancy concentration in Ni-doped samples, contributing to greater surface reactivity via enhanced active oxygen species. The increased surface area, the presence of surface dangling bonds of the TVA-processed samples further contributes to the observed performance. The exceptional sensing ability of TVA-processed NZO is primarily attributed to its robust ferromagnetic characteristics, establishing TVA as a promising route for tuning the multifunctional properties of oxide semiconductors.

丙酮（CH3-CO-CH3）是一种高度易燃且应用广泛的工业溶剂，在低温下快速响应和回收时间的检测仍然是一个挑战。本研究考察了Ni和Co掺杂ZnO （NZO和CZO）的磁性行为对室温（RT）热振动退火和振动干淬（TVA）工艺处理的丙酮传感性能的影响。对比分析表明，与CZO相比，经过TVA处理的NZO具有更好的铁磁行为和增强的气敏性能，尽管两者的晶粒尺寸相似。当暴露于10ppm的丙酮时，NZO比CZO表现出更高的灵敏度。值得注意的是，通过TVA处理的NZO和CZO颗粒在RT下比传统退火的颗粒具有更高的灵敏度和更短的响应/恢复时间。经TVA处理的NZO传感器具有~ 37%的灵敏度，在rt下的快速响应时间为~ 23 s。在气体灵敏度和磁滞的平方比之间观察到很强的相关性，突出了磁特性在气体传感行为中的重要作用。温度-传感行为表明，在居里温度附近，丙酮在ni掺杂ZnO中的响应受耦合磁电子相互作用的控制。此外，光致发光分析显示，ni掺杂样品中的氧空位浓度增加，通过增强的活性氧有助于提高表面反应性。tva处理样品的表面积增加，表面悬垂键的存在进一步有助于观察到的性能。TVA处理的NZO的特殊传感能力主要归功于其强大的铁磁特性，使TVA成为调节氧化物半导体多功能特性的有前途的途径。

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引用次数: 0

Thermomagnetic transport and field-tunable figures of merit in GaAs/AlGaAs superlattices GaAs/AlGaAs超晶格中的热磁输运和场可调谐参量

IF 3 Q2 PHYSICS, CONDENSED MATTER

Micro and Nanostructures

Pub Date : 2026-01-28 DOI: 10.1016/j.micrna.2026.208583

D. Sekyi-Arthur , S.Y. Mensah , K.A. Dompreh , F. Amo-Mensah

Herein, we present a comprehensive theoretical and computational investigation of both the longitudinal (

Z T_{x x}

) and off-diagonal (

Z T_{x y}

) thermoelectric performance of GaAs–AlGaAs superlattices subjected to combined alternating electric and perpendicular magnetic fields. Using the semiclassical Boltzmann transport framework, the model incorporates miniband electron dynamics, impurity and phonon scattering, donor activation, and both electronic and lattice contributions to heat transport. The applied magnetic field couples the longitudinal and transverse channels, giving rise to non-zero off-diagonal thermopower (

α_{x y}

) and electrical conductivity (

σ_{x y}

) components, while simultaneously modifying the longitudinal thermoelectric response (

α_{x x}

,

σ_{x x}

). Parametric analyses across temperature, miniband width, carrier density, chemical potential, and lattice thermal conductivity reveal that quantum confinement and magneto-thermoelectric coupling can substantially enhance both

Z T_{x x}

and

Z T_{x y}

, with the transverse component showing particularly strong gains at moderate magnetic fields at sub-room temperatures. These results demonstrate the potential of engineered GaAs–AlGaAs superlattices for high-efficiency longitudinal and transverse thermoelectric energy conversion, providing a predictive framework for optimising anisotropic thermoelectricity in low-dimensional semiconductor systems.

在此，我们对GaAs-AlGaAs超晶格在交变电场和垂直磁场联合作用下的纵向（ZTxx）和非对角线（ZTxy）热电性能进行了全面的理论和计算研究。利用半经典玻尔兹曼输运框架，该模型结合了小带电子动力学、杂质和声子散射、供体激活以及电子和晶格对热输运的贡献。外加磁场耦合纵向和横向通道，产生非零的非对角线热功率（αxy）和电导率（σxy）分量，同时改变了纵向热电响应（αxx, σxx）。温度、微带宽度、载流子密度、化学势和晶格导热系数的参数分析表明，量子约束和磁热电耦合可以显著增强ZTxx和ZTxy，其中横向分量在亚室温中等磁场下表现出特别强的增益。这些结果证明了工程GaAs-AlGaAs超晶格在高效纵向和横向热电能量转换方面的潜力，为优化低维半导体系统中的各向异性热电提供了预测框架。

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引用次数: 0

TCAD-DFT based modeling and optimization of Graphene/Silicon Schottky junction solar cells 基于TCAD-DFT的石墨烯/硅肖特基结太阳能电池建模与优化

IF 3 Q2 PHYSICS, CONDENSED MATTER

Micro and Nanostructures

Pub Date : 2026-01-23 DOI: 10.1016/j.micrna.2026.208581

Manoj Kumar , Purnendu Shekhar Pandey , Gvs Manoj Kumar , Akash Kumar Pradhan , M. Sudhakara Reddy , Anita Gehlot

This study presents a comprehensive investigation of graphene/silicon (Gr/Si) Schottky junction solar cells using an integrated approach that combines density functional theory (DFT) with Technology Computer-Aided Design (TCAD, Silvaco) simulations. DFT calculations were used to extract key optoelectronic properties of graphene, including refractive index, extinction coefficient, absorption, and interface charge density, which were incorporated into Silvaco TCAD simulations to model device behavior. The influence of graphene thickness, interfacial engineering, and graphene electron affinity on photovoltaic performance was systematically examined. The results show that graphene thickness strongly controls the tradeoff between optical transparency and electrical conductivity, with three graphene layers providing optimal performance. At this thickness, the device achieves a short-circuit current density of ∼23 mA/cm² and a fill factor of ∼83 %, while thicker layers reduce efficiency due to increased optical losses and recombination. Mechanical stress analysis reveals that increasing graphene layers amplifies interfacial stress and trap density, whereas TiO₂ emerges as the most effective stress-relieving interface layer due to its low residual stress and reduced defect formation. Tuning the graphene electron affinity (χ_Gr) from 4.1 to 4.7 eV, an optimum is observed at χ_Gr ≈ 4.4 eV (work function ≈ 5.5 eV), yielding a maximum power conversion efficiency of 19.26 %, with a short-circuit current density of 25 mA/cm², an open-circuit voltage of 0.92 V, and a fill factor of 83.6 %. These findings demonstrate that controlled graphene thickness, TiO₂-based interface passivation, and electron-affinity optimization are key to achieving high-efficiency Gr/Si Schottky junction solar cells.

本研究采用密度泛函理论（DFT）和计算机辅助设计（TCAD, Silvaco）模拟相结合的综合方法，对石墨烯/硅（Gr/Si）肖特基结太阳能电池进行了全面的研究。DFT计算用于提取石墨烯的关键光电特性，包括折射率、消光系数、吸收和界面电荷密度，并将其纳入Silvaco TCAD模拟中以模拟器件行为。系统考察了石墨烯厚度、界面工程和石墨烯电子亲和对光伏性能的影响。结果表明，石墨烯厚度在很大程度上控制了光学透明度和导电性之间的权衡，其中三层石墨烯具有最佳性能。在这种厚度下，器件实现了~ 23 mA/cm2的短路电流密度和~ 83%的填充系数，而较厚的层由于增加的光学损耗和复合而降低了效率。机械应力分析表明，石墨烯层数的增加增加了界面应力和陷阱密度，而TiO2由于其低残余应力和减少缺陷形成而成为最有效的应力消除界面层。将石墨烯的电子亲和度（χGr）从4.1 eV调整到4.7 eV，在χGr≈4.4 eV（功函数≈5.5 eV）处达到最优，得到的最大功率转换效率为19.26%，短路电流密度为25 mA/cm2，开路电压为0.92 V，填充系数为83.6%。这些发现表明，控制石墨烯厚度、tio2基界面钝化和电子亲和优化是实现高效Gr/Si肖特基结太阳能电池的关键。

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引用次数: 0

Tunable properties of PtSe2/ZrS2 heterojunction and Te-doped PtSe2/ZrS2 heterojunction PtSe2/ZrS2异质结和te掺杂PtSe2/ZrS2异质结的可调谐特性

IF 3 Q2 PHYSICS, CONDENSED MATTER

Micro and Nanostructures

Pub Date : 2026-01-20 DOI: 10.1016/j.micrna.2026.208579

Hangqing Wu, Lu Yang, Hang Su, Liqun Wu

This study systematically investigates the synergistic modulation effects of Te doping and perpendicular external electric fields on the electronic structure and optical response of PtSe₂/ZrS₂ two-dimensional heterostructures using first-principles density functional theory (DFT). Three representative stable configurations were selected for comparison: A1 (undoped PtSe₂/ZrS₂), B1 (Te substituting S atoms in the ZrS₂ layer), and C1 (Te substituting Se atoms in the PtSe₂ layer). Band structure and density of states results indicate that all three models exhibit typical Type-II band alignment characteristics with effective carrier spatial separation. Under zero electric field, the band gaps of A1, B1, and C1 are 0.444 eV, 0.319 eV, and 0.226 eV, respectively, with C1 demonstrating a direct band gap more favorable for photovoltaic conversion. Further investigations reveal that an applied electric field significantly modulates the band structure and enables continuous bandgap tuning. Under negative electric fields, the C1 bandgap increases to 0.609 eV (−0.6 V/Å), demonstrating a broad tunability range and high response sensitivity. Regarding optical properties, Te doping enhances the static dielectric constant, while applied electric fields induce peak position shifts and intensity modulation in absorption and reflection spectra. This study provides quantitative theoretical insights into the “doping-electric field” coupling regulation mechanism within PtSe₂/ZrS₂ heterostructures, laying a foundation for structural design and performance optimization of tunable two-dimensional optoelectronic devices.

本文采用第一性原理密度泛函理论（DFT）系统地研究了Te掺杂和垂直外电场对PtSe2/ZrS2二维异质结构的电子结构和光响应的协同调制效应。我们选择了三种具有代表性的稳定构型进行比较：A1（未掺杂PtSe2/ZrS2）、B1 （Te取代ZrS2层中的S原子）和C1 （Te取代PtSe2层中的Se原子）。能带结构和态密度结果表明，三种模式均表现出典型的ii型能带对准特征，具有有效的载流子空间分离。在零电场条件下，A1、B1和C1的带隙分别为0.444 eV、0.319 eV和0.226 eV，其中C1为直接带隙，更有利于光伏转换。进一步的研究表明，外加电场可以显著调节带结构并实现连续带隙调谐。在负电场作用下，C1带隙增大到0.609 eV （- 0.6 V/Å），具有较宽的可调范围和较高的响应灵敏度。在光学性能方面，Te掺杂提高了静态介电常数，外加电场引起吸收和反射光谱的峰位偏移和强度调制。本研究为PtSe2/ZrS2异质结构中“掺杂-电场”耦合调控机制提供了定量的理论见解，为可调谐二维光电器件的结构设计和性能优化奠定了基础。

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引用次数: 0

Dopant-induced property modifications in aqueous-synthesized SiC nanoparticles 掺杂剂诱导的水合成碳化硅纳米颗粒的性能修饰

IF 3 Q2 PHYSICS, CONDENSED MATTER

Micro and Nanostructures

Pub Date : 2026-01-20 DOI: 10.1016/j.micrna.2026.208580

M.M. Esmael , M.S. Omar , F. Degdelen

In this study, aluminum (Al), vanadium (V), and nitrogen (N) doped silicon carbide (SiC) nanoparticles were successfully synthesized using pulsed laser ablation in water (PLAL), a green and surfactant-free method. Doping was used to enhance the optical and structural properties of SiC nanoparticles. Ultraviolet–visible spectroscopy confirmed that N, Al, and V doping systematically narrowed the optical energy gap of SiC nanoparticles from 3.2 eV (undoped) to 2.37–3.11 eV, depending on the dopant type and concentration. Fourier transform infrared spectroscopy confirmed the preservation of Si–C bonds and revealed dopant-specific vibrational features, while the absence of secondary oxide or nitride phases indicated clean substitutional doping. Field-emission scanning electron microscopy showed that Al-doped (∼15 nm) and N-doped (∼14 nm) particles exhibited reduced size and enhanced crystallinity. In contrast, V-doping yielded larger (∼30 nm) particles with deep-level defects. Energy-dispersive X-ray spectroscopy confirmed successful incorporation of Al, N, and V, with dopant-specific peaks and variations in the Si:C ratio, indicating substitutional doping and defect-complex formation. Hall-effect measurements confirmed the semiconducting behavior of SiC nanoparticles, showing that conductivity increased with temperature (300–500 K) while mobility decreased due to phonon scattering. Doping enhanced conductivity but reduced mobility through impurity scattering, with Al- and N-doped SiC exhibiting the most favorable balance. After standardizing the particle size at 8 nm to remove size effects, Eg decreased from 3.2 eV (undoped) to 2.41 eV (N–SiC), 2.48 eV (Al–SiC), and 2.8 eV (V–SiC). The reduction indicates that dopants introduce localized states within the band gap, with nitrogen producing the most substantial effect. These results confirm that doping effectively tailors the electronic structure of SiC nanoparticles.

在本研究中，利用脉冲激光烧蚀水中（PLAL）成功合成了铝（Al）、钒(V)和氮(N)掺杂的碳化硅（SiC）纳米颗粒，这是一种绿色且无表面活性剂的方法。采用掺杂的方法增强了SiC纳米颗粒的光学性能和结构性能。紫外可见光谱证实，N、Al和V的掺杂系统地将SiC纳米粒子的光能隙从3.2 eV（未掺杂）缩小到2.37-3.11 eV，这取决于掺杂类型和浓度。傅里叶变换红外光谱证实了Si-C键的保存，并揭示了掺杂物特有的振动特征，而没有二级氧化物或氮化物相表明是干净的取代掺杂。场发射扫描电镜显示，掺al （~ 15 nm）和掺n （~ 14 nm）的颗粒尺寸减小，结晶度增强。相比之下，v掺杂产生更大（~ 30 nm）的颗粒，具有深层次缺陷。能量色散x射线光谱证实了Al， N和V的成功掺入，掺杂物特异性峰和Si:C比的变化表明取代掺杂和缺陷复合物的形成。霍尔效应测量证实了SiC纳米颗粒的半导体行为，表明电导率随着温度（300-500 K）的升高而增加，而迁移率由于声子散射而降低。掺杂提高了电导率，但通过杂质散射降低了迁移率，其中Al和n掺杂的SiC表现出最有利的平衡。在8 nm处对粒径进行标准化以消除粒径效应后，Eg从3.2 eV（未掺杂）降至2.41 eV （N-SiC）、2.48 eV （Al-SiC）和2.8 eV （V-SiC）。还原表明掺杂剂在带隙内引入了局域态，其中氮的影响最大。这些结果证实了掺杂可以有效地调整碳化硅纳米颗粒的电子结构。

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引用次数: 0

First-principles modelling of physical characteristics of SiX3H8 (X = Ti, V, Cr, Mn, Fe) hydrides for hydrogen storage and energy harvesting applications 用于储氢和能量收集的SiX3H8 （X = Ti， V, Cr, Mn, Fe）氢化物物理特性第一性原理建模

IF 3 Q2 PHYSICS, CONDENSED MATTER

Micro and Nanostructures

Pub Date : 2026-01-17 DOI: 10.1016/j.micrna.2026.208577

Bilal Ahmed , Muhammad Bilal Tahir , Gharam A. Alharshan

This paper offers a thorough first-principles examination of the structural, electronic, optical, mechanical, magnetic, thermodynamic, and hydrogen storage characteristics of SiX₃H₈ (X = Ti, V, Cr, Mn, Fe) hydrides utilizing density functional theory (DFT). All of the compounds crystallize in a cubic perovskite-type framework (space group Pm3 m) and have negative formation enthalpies and phonon spectra that don't have any imaginary modes. This shows that they are stable in both thermodynamic and dynamic terms. Electronic band structures and density-of-states investigations demonstrate metallic behavior in all hydrides, characterized by strong d-orbital contributions near the Fermi level, which enable fast charge transfer during hydrogen adsorption and desorption. Optical computations show that the materials have strong dielectric responses, high refractive indices, high absorption coefficients, and high optical conductivity. This suggests that they could be used for both hydrogen storage and optoelectronic applications. Mechanical tests show that all of the compounds meet Born stability standards and are brittle with different levels of anisotropy. SiMn₃H₈ is the stiffest of the bunch. Thermodynamic data indicate consistent increases in internal energy, entropy, and heat capacity as temperature rises. The estimated gravimetric hydrogen storage capacities (3.96–4.49 wt%) surpass conventional material-level screening criteria yet fall short of the U.S. DOE final system-level target (∼6.5 wt%), suggesting that SiX₃H₈ hydrides are promising candidate materials necessitating further optimization for practical hydrogen storage systems. The computed desorption temperatures (341–441 K) are also within or close to practical operational limits. The structural stability, metallicity, favorable thermodynamic behavior, and competitive hydrogen storage features of SiX₃H₈ hydrides make them strong candidates for advanced solid-state hydrogen H₂ devices and energy-related applications that do more than one thing.

本文利用密度泛函理论（DFT）对SiX3H8 （X = Ti， V, Cr, Mn, Fe）氢化物的结构、电子、光学、机械、磁性、热力学和储氢特性进行了全面的第一性原理研究。所有化合物都在立方钙钛矿型框架（空间群Pm3 m）中结晶，并且具有负的形成焓和没有任何虚模的声子谱。这表明它们在热力学和动力学方面都是稳定的。电子能带结构和态密度研究证明了所有氢化物的金属行为，其特征是在费米能级附近的强d轨道贡献，这使得氢吸附和解吸过程中的快速电荷转移成为可能。光学计算表明，该材料具有强的介电响应、高折射率、高吸收系数和高导电性。这表明它们可以用于储氢和光电子应用。力学试验结果表明，所有化合物均符合波恩稳定性标准，具有不同程度的各向异性脆性。SiMn3H8是其中最硬的。热力学数据表明，随着温度的升高，内能、熵和热容不断增加。估计的重量储氢容量（3.96-4.49 wt%）超过了传统的材料级筛选标准，但低于美国能源部最终的系统级目标（~ 6.5 wt%），这表明SiX3H8氢化物是有希望的候选材料，需要进一步优化实际的储氢系统。计算的解吸温度（341-441 K）也在或接近实际操作极限。SiX3H8氢化物的结构稳定性、金属丰度、良好的热力学行为和具有竞争力的储氢特性使其成为先进固态氢H2器件和能源相关应用的强有力候选者。

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引用次数: 0

First-principles study of hexagonal lithium carbonate (Li2CO3) 六方碳酸锂（Li2CO3）的第一性原理研究

IF 3 Q2 PHYSICS, CONDENSED MATTER

Micro and Nanostructures

Pub Date : 2026-01-16 DOI: 10.1016/j.micrna.2026.208575

Nzar Rauf Abdullah , Shaho M. Rasul , Bashdar Rahman Pirot

In this study, the structural, stability, thermal, electronic, and optical properties of lithium carbonate (Li

_{2}

CO

_{3}

) are investigated using density functional theory (DFT) and ab initio molecular dynamics (AIMD) simulations. Formation energy, phonon dispersion, elastic constants, and AIMD simulations confirm the energetic, dynamical, mechanical, and thermal stability of the structure, respectively. Bonding analysis through the electron localization function (ELF) reveals a mixed bonding nature, with ionic Li-O interactions and covalent C-O bonds. The electronic band structure and partial density of states (PDOS) indicate that Li

_{2}

CO

_{3}

has a wide Kohn–Sham band gap of 3.783 eV (PBE) and 6.013 eV (HSE06). Calculations of the complex dielectric function, refractive index, and optical conductivity show that Li

_{2}

CO

_{3}

exhibits a larger optical band gap of 4.45 eV (PBE), arising from its indirect band-gap nature. Thermodynamic and transport properties, including heat capacity, phonon PDOS, entropy, Seebeck coefficient, electrical conductivity, and power factor, are analyzed across low- and high-temperature regimes. At low temperatures (

T \leq 200

K), the power factor increases with temperature due to enhanced thermally activated electrical conductivity, highlighting potential for sensitive thermopile sensors. At elevated temperatures (

T > 200

K), the heat capacity approaches 23.25 J/mol K at 1000 K, just below the Dulong–Petit limit, making Li

_{2}

CO

_{3}

a promising candidate for thermal storage applications.

在本研究中，利用密度泛函理论（DFT）和从头算分子动力学（AIMD）模拟研究了碳酸锂（Li2CO3）的结构、稳定性、热、电子和光学性质。形成能、声子色散、弹性常数和AIMD模拟分别证实了该结构的能量、动力学、力学和热稳定性。通过电子定位函数（ELF）的成键分析揭示了离子Li-O相互作用和共价C-O键的混合成键性质。电子能带结构和偏态密度（PDOS）表明Li2CO3具有3.783 eV （PBE）和6.013 eV （HSE06）的宽Kohn-Sham带隙。复介电函数、折射率和光电导率的计算表明，由于Li2CO3的间接带隙性质，其光学带隙较大，为4.45 eV （PBE）。热力学和输运性质，包括热容量、声子PDOS、熵、塞贝克系数、电导率和功率因数，在低温和高温条件下进行了分析。在低温（T≤200 K）下，由于热激活电导率增强，功率因数随温度升高而增加，突出了敏感热电堆传感器的潜力。在高温（200 K）下，Li2CO3在1000 K时的热容接近23.25 J/mol K，刚好低于Dulong-Petit极限，这使得Li2CO3成为储热应用的有希望的候选者。

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引用次数: 0

Impact of spacer dielectric materials on advanced stacked nanosheet field effect transistors 间隔介质材料对先进叠置纳米片场效应晶体管的影响

IF 3 Q2 PHYSICS, CONDENSED MATTER

Micro and Nanostructures

Pub Date : 2026-01-16 DOI: 10.1016/j.micrna.2026.208576

M. Balasubrahmanyam , Ekta Goel , Kunal Singh , Sanjay Kumar

This study investigates several spacer materials, such as single-k (Air and SiO₂) and dual-k (SiO₂+HfO₂, and Si₃N₄+HfO₂) analyzing their influence on DC/Analog performance of three advanced nanosheet FETs i.e. SNSFET, HS NSFET, and PHS NSFET utilizing properly calibrated Sentaurus TCAD simulation models. Findings demonstrate that high-k spacers enhance device scalability, but low-k spacers diminish parasitic capacitance in high-speed applications. Combination of Si₃N₄ and HfO₂ spacer material gives better results on DC characteristics (ON current (I_ON), I_ON/I_OFF ratio, subthreshold swing (SS), drain induced barrier lowering (DIBL)) and Aanalo/RF (radio frequency) characteristics (transconductance (g_m), cutoff frequency (f_T), gain badwidth product (GBP), and transconductance frequency product (TFP)) compared to spacer materials of Air, SiO₂ and SiO₂+HfO₂. This study offers insights into the selection of spacer materials for next generation nanoscale devices, enhancing reliability, and device performance.

本研究研究了几种间隔材料，如单k（空气和SiO2）和双k (SiO2+HfO2和Si3N4+HfO2)，利用适当校准的Sentaurus TCAD仿真模型，分析了它们对三种先进纳米片场效应管（snfet， HS NSFET和PHS NSFET） DC/Analog性能的影响。研究结果表明，高k间隔提高了器件的可扩展性，但低k间隔降低了高速应用中的寄生电容。与Air、SiO2和SiO2+HfO2的间隔材料相比，Si3N4和HfO2间隔材料的组合在直流特性（on电流（ION）、ION/IOFF比、亚阈值摆幅（SS）、漏极诱导势垒降低（DIBL））和Aanalo/RF（射频）特性（跨导（gm）、截止频率（fT）、增益宽积（GBP）和跨导频率积（TFP））方面取得了更好的结果。这项研究为下一代纳米级器件的间隔材料选择提供了见解，提高了可靠性和器件性能。

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引用次数: 0

First-principles insights into the structural, electronic, and optical properties of Ag, Zn, and Ag/Zn co-doped anatase TiO2 for enhanced photocatalysis 对Ag、Zn和Ag/Zn共掺杂锐钛矿TiO2增强光催化的结构、电子和光学性质的第一性原理见解

IF 3 Q2 PHYSICS, CONDENSED MATTER

Micro and Nanostructures

Pub Date : 2026-01-16 DOI: 10.1016/j.micrna.2026.208574

Isara Kotutha , Apiwat Boonkaung , Wutthikrai Busayaporn , Rakchat Klinkla , Theeranuch Nachaithong , Pirapat Waritkraikul , Wutthigrai Sailuam

The structural, electronic, and optical properties of pristine and doped anatase TiO₂ were investigated using first-principles density functional theory (DFT). Pristine TiO₂ exhibits an indirect band gap of ∼1.93 eV from O-2p → Ti-3d transitions. Formation energy analysis shows that Ag doping is more favorable than Zn, with Zn stabilizing intralayer sites while Ag tends to cluster intralayer due to strong Ag–Ag attraction. Binding energy calculations confirm attractive interactions in Ag–Ag intralayer and Zn–Zn interlayer configurations, while Ag/Zn co-doping provides cooperative stabilization. In co-doped systems, Ag clusters intralayer while Zn stabilizes interlayer distortions, producing negative binding energies that suppress excessive Ag clustering, enhance dopant homogeneity, and generate controlled defect states, thereby improving structural stability and photocatalytic performance. Electronic structure analysis reveals that Ag and Zn introduce acceptor-like states Ti-3d/Ag-4d/O-2p states near the VBM, while co-doped systems form synergistic hybrid states (∼0.65–0.73 eV). Optical analyses show that pristine TiO₂ has a static dielectric constant ε₁(0) of ∼7, and that Ag, Zn and Ag/Zn co-doping significantly enhance visible absorption (1.5–3.0 eV), underscoring codoping as a promising strategy for efficient TiO₂-based photocatalysts.

利用第一性原理密度泛函理论（DFT）研究了原始和掺杂锐钛矿TiO2的结构、电子和光学性质。原始TiO2在O-2p→Ti-3d跃迁过程中表现出约1.93 eV的间接带隙。形成能分析表明，Ag掺杂比Zn更有利，Zn稳定层内位置，而Ag由于银银之间的强烈吸引力，更倾向于在层内聚集。结合能计算证实了Ag - Ag层内和Zn - Zn层间的相互吸引作用，而Ag/Zn共掺杂提供了协同稳定。在共掺杂体系中，Ag在层内聚集，而Zn稳定层间扭曲，产生负结合能，抑制过量的Ag聚集，增强掺杂物的均匀性，并产生可控的缺陷态，从而提高结构稳定性和光催化性能。电子结构分析表明，Ag和Zn在VBM附近引入了类受体态Ti-3d/Ag-4d/O-2p态，而共掺杂体系形成了协同杂化态（~ 0.65 ~ 0.73 eV）。光学分析表明，原始TiO2的静态介电常数ε1(0)为~ 7，Ag、Zn和Ag/Zn共掺杂显著提高了可见光吸收（1.5 ~ 3.0 eV），这表明共掺杂是制备高效TiO2基光催化剂的一种很有前景的策略。

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引用次数: 0

A numerical investigation on the performance of D/E-mode GaN HEMTs with nitride stress films 氮化应力薄膜的D/ e型GaN hemt性能的数值研究

IF 3 Q2 PHYSICS, CONDENSED MATTER

Micro and Nanostructures

Pub Date : 2026-01-14 DOI: 10.1016/j.micrna.2026.208572

Xing Wang , Yifei Wang , Guanyu Wang , Chunyu Zhou , Bo Ye , Song Shi

In this work, the impact of additional uniaxial stress on both D-mode and E-mode GaN HEMTs has been investigated. It develops an equivalent conversion model linking additional stress to the Al composition in AlGaN barrier layers, validated through theoretical calculations and TCAD simulations. Using this model, the TCAD tool was employed to analyze the effects of varying stress types and magnitudes on device performance. Simulations revealed that applying a 2 GPa uniaxial compressive stress optimized performance for both device types. Compared to stress-free conditions, D-mode HEMT showed improvements of 60 % in threshold voltage, 1 % in peak transconductance, and 6 % in breakdown voltage, while E-mode HEMT exhibited increases of 25 %, 4 %, and 9 %, respectively. The study also explored the influence of additional uniaxial stress on the voltage transfer characteristics of complementary GaN HEMT inverters.

在这项工作中，研究了额外的单轴应力对d型和e型GaN hemt的影响。它建立了一个等效的转换模型，将额外的应力与AlGaN阻挡层中的Al成分联系起来，并通过理论计算和TCAD模拟进行了验证。利用该模型，利用TCAD工具分析了不同应力类型和大小对器件性能的影响。模拟结果表明，施加2gpa的单轴压应力可优化两种器件的性能。与无应力条件相比，d模式HEMT的阈值电压提高了60%，峰值跨导率提高了1%，击穿电压提高了6%，而e模式HEMT分别提高了25%，4%和9%。本研究还探讨了附加单轴应力对互补GaN HEMT逆变器电压传递特性的影响。

引用次数: 0