Pub Date : 2026-04-01Epub Date: 2026-01-12DOI: 10.1016/j.micrna.2026.208569
Zhen Cui , Hongrun Xu , Xinmei Wang , Leyan Xia , Shuang Zhang , Lu Wang
To address the common issues of existing chiral absorbers, such as complex structures, narrow bandwidths, and the difficulty of tuning circular dichroism (CD), this paper proposes an innovative three-layer tunable chiral absorber based on a composite structure of low-conductivity Vanadium Dioxide(VO2) and highly conductive gold. The designed structure achieves highly selective absorption (CD > 0.8) within a bandwidth of 2.67 THz, while its mirror-symmetric counterpart exhibits an opposite CD response. By thermally tuning the conductivity of VO2, continuous and reversible modulation of CD is realized, with a modulation depth exceeding 0.97 in the range of 5–9 THz. Analyses based on the equivalent circuit model, impedance matching principle, and electric field distribution are conducted to reveal the underlying absorption mechanism. Furthermore, the effects of structural parameters, incident angle, and azimuth angle on the CD spectrum are systematically investigated. This paper presents a new approach for designing tunable broadband chiral absorbers and demonstrates promising potential applications in electromagnetic stealth, terahertz imaging, filtering, and 5G/6G communication systems.
{"title":"A theoretical investigation of a dynamically tunable terahertz Chiral broadband absorber based on VO2","authors":"Zhen Cui , Hongrun Xu , Xinmei Wang , Leyan Xia , Shuang Zhang , Lu Wang","doi":"10.1016/j.micrna.2026.208569","DOIUrl":"10.1016/j.micrna.2026.208569","url":null,"abstract":"<div><div>To address the common issues of existing chiral absorbers, such as complex structures, narrow bandwidths, and the difficulty of tuning circular dichroism (CD), this paper proposes an innovative three-layer tunable chiral absorber based on a composite structure of low-conductivity Vanadium Dioxide(VO<sub>2</sub>) and highly conductive gold. The designed structure achieves highly selective absorption (CD > 0.8) within a bandwidth of 2.67 THz, while its mirror-symmetric counterpart exhibits an opposite CD response. By thermally tuning the conductivity of VO<sub>2</sub>, continuous and reversible modulation of CD is realized, with a modulation depth exceeding 0.97 in the range of 5–9 THz. Analyses based on the equivalent circuit model, impedance matching principle, and electric field distribution are conducted to reveal the underlying absorption mechanism. Furthermore, the effects of structural parameters, incident angle, and azimuth angle on the CD spectrum are systematically investigated. This paper presents a new approach for designing tunable broadband chiral absorbers and demonstrates promising potential applications in electromagnetic stealth, terahertz imaging, filtering, and 5G/6G communication systems.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"212 ","pages":"Article 208569"},"PeriodicalIF":3.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145981293","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 : 2026-04-01Epub Date: 2026-01-06DOI: 10.1016/j.micrna.2026.208566
Osamah Alsalman
This research presents a graphene-based highly sensitive and machine learning-optimized plasmonic biosensor specifically designed for the early detection of adrenal cancer. The proposed sensor architecture achieves an outstanding sensitivity of 1429 nm/RIU, outperforming many state-of-the-art biosensors. It leverages strong plasmonic resonance shifts resulting from refractive index changes caused by biomolecular interactions related to adrenal cancer markers. To further enhance performance, parametric optimization of structural dimensions—such as resonator height and material layer thicknesses—was conducted, supported by a machine learning (ML) regression model. The model achieved a high prediction accuracy with an R2 value of 0.99, indicating near-perfect agreement between simulated and predicted outcomes. Key sensing performance indicators including FOM, Q-Factor and DL were thoroughly analyzed, confirming the sensor’s superiority in precision and detection capability. The ML-assisted design not only accelerated the optimization process but also improved the robustness and adaptability of the biosensor across different operating conditions. The sensor’s excellent spectral response, combined with real-time and label-free detection capabilities, makes it a strong candidate for clinical diagnostics. The sensor has high absorptance and stable spectral response in near-normal and moderate incidence angles, the realistic working parameters of biosensing. Nevertheless, the absorptance is lower at very oblique angles (θ > 70–80°), and performance falls below 0.5 at 80° approximately. This is a constraint of plasmonic resonance coupling and has no impact on the applicability of the sensor in real detection situations where near-normal incidence is generally used. This work demonstrates the promising application of AI-driven sensor design in developing next-generation biosensors for ultra-sensitive and specific detection of adrenal cancer biomarkers.
{"title":"Intelligent plasmonic sensing platform for adrenal cancer: Graphene-based machine learning optimization and high-performance detection","authors":"Osamah Alsalman","doi":"10.1016/j.micrna.2026.208566","DOIUrl":"10.1016/j.micrna.2026.208566","url":null,"abstract":"<div><div>This research presents a graphene-based highly sensitive and machine learning-optimized plasmonic biosensor specifically designed for the early detection of adrenal cancer. The proposed sensor architecture achieves an outstanding sensitivity of 1429 nm/RIU, outperforming many state-of-the-art biosensors. It leverages strong plasmonic resonance shifts resulting from refractive index changes caused by biomolecular interactions related to adrenal cancer markers. To further enhance performance, parametric optimization of structural dimensions—such as resonator height and material layer thicknesses—was conducted, supported by a machine learning (ML) regression model. The model achieved a high prediction accuracy with an R<sup>2</sup> value of 0.99, indicating near-perfect agreement between simulated and predicted outcomes. Key sensing performance indicators including FOM, Q-Factor and DL were thoroughly analyzed, confirming the sensor’s superiority in precision and detection capability. The ML-assisted design not only accelerated the optimization process but also improved the robustness and adaptability of the biosensor across different operating conditions. The sensor’s excellent spectral response, combined with real-time and label-free detection capabilities, makes it a strong candidate for clinical diagnostics. The sensor has high absorptance and stable spectral response in near-normal and moderate incidence angles, the realistic working parameters of biosensing. Nevertheless, the absorptance is lower at very oblique angles (θ > 70–80°), and performance falls below 0.5 at 80° approximately. This is a constraint of plasmonic resonance coupling and has no impact on the applicability of the sensor in real detection situations where near-normal incidence is generally used. This work demonstrates the promising application of AI-driven sensor design in developing next-generation biosensors for ultra-sensitive and specific detection of adrenal cancer biomarkers.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"212 ","pages":"Article 208566"},"PeriodicalIF":3.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145929326","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 : 2026-04-01Epub Date: 2026-01-16DOI: 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 (LiCO) 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 LiCO 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 LiCO 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 ( K), the power factor increases with temperature due to enhanced thermally activated electrical conductivity, highlighting potential for sensitive thermopile sensors. At elevated temperatures ( K), the heat capacity approaches 23.25 J/mol K at 1000 K, just below the Dulong–Petit limit, making LiCO 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。
{"title":"First-principles study of hexagonal lithium carbonate (Li2CO3)","authors":"Nzar Rauf Abdullah , Shaho M. Rasul , Bashdar Rahman Pirot","doi":"10.1016/j.micrna.2026.208575","DOIUrl":"10.1016/j.micrna.2026.208575","url":null,"abstract":"<div><div>In this study, the structural, stability, thermal, electronic, and optical properties of lithium carbonate (Li<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>CO<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>) 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<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>CO<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span> 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<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>CO<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span> 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 (<span><math><mrow><mi>T</mi><mo>≤</mo><mn>200</mn></mrow></math></span> K), the power factor increases with temperature due to enhanced thermally activated electrical conductivity, highlighting potential for sensitive thermopile sensors. At elevated temperatures (<span><math><mrow><mi>T</mi><mo>></mo><mn>200</mn></mrow></math></span> K), the heat capacity approaches 23.25 J/mol K at 1000 K, just below the Dulong–Petit limit, making Li<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>CO<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span> a promising candidate for thermal storage applications.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"212 ","pages":"Article 208575"},"PeriodicalIF":3.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146026243","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 : 2026-04-01Epub Date: 2026-01-21DOI: 10.1016/j.micrna.2026.208578
Amina Chaib, Mohammed Amrani, Zineb Benamara
We study an Ag/poly-Si (low-pressure chemical vapor deposition, LPCVD)/indium tin oxide (ITO) Schottky diode on glass using current–voltage (I–V) measurements at 300 K, in the dark and under helium–neon (He–Ne) laser illumination (λ = 632.8 nm; incident optical power at the device plane, P_in ≈ 0.2 mW). Under illumination, a net photocurrent (I_ph) ≈ 2.7 × 10−6 A is obtained at −2 V, yielding an optical contrast I_light/I_dark ∼ 103, with a responsivity (R) ≈ 1.33 × 10−2 A W−1 and a specific detectivity (D∗) ≈ 1.15 × 109 Jones at (−2 V). To interpret the illuminated characteristics, we develop a two-dimensional (2D) drift–diffusion model (Poisson + continuity) including optical generation (parameter powrm, normalized illumination level) and Shockley–Read–Hall (SRH) recombination through interface and grain-boundary traps (total trap density NT, with NTA and NTD). The parametric analysis shows that optical generation sets the photocurrent amplitude, the donor concentration (ND) governs forward conduction, and NT controls recombination losses, strongly impacting the forward branch and the open-circuit voltage V_oc. No combination of these parameters reproduces the experimental reverse-bias behavior without impact ionization; introducing this mechanism captures the high-field rise and curvature while preserving the forward branch. Using ND independently extracted from capacitance–voltage (C–V) measurements (1 MHz) and keeping the other inputs fixed from independent characterizations, the best agreement is obtained for NTA = 2.85 × 1012 cm−2 and NTD = 3.25 × 1012 cm−2, supporting the overall consistency of the 2D model and the coupled influence of optical generation, transport, recombination, and impact ionization on the illuminated I–V characteristics. Compared with prior reports on Ag/poly-Si diodes, this work combines systematic dark/illuminated measurements on an Ag/poly-Si/ITO device fabricated on glass with a dedicated 2D drift–diffusion model that incorporates trap-assisted recombination and impact ionization, enabling a physically constrained interpretation of the photoresponse and extracted parameters.
{"title":"Optical response of Ag/poly-Si/ITO Schottky diodes under illumination: experiment and 2D modeling","authors":"Amina Chaib, Mohammed Amrani, Zineb Benamara","doi":"10.1016/j.micrna.2026.208578","DOIUrl":"10.1016/j.micrna.2026.208578","url":null,"abstract":"<div><div>We study an Ag/poly-Si (low-pressure chemical vapor deposition, LPCVD)/indium tin oxide (ITO) Schottky diode on glass using current–voltage (I–V) measurements at 300 K, in the dark and under helium–neon (He–Ne) laser illumination (<em>λ</em> = 632.8 nm; incident optical power at the device plane, <em>P_in</em> ≈ 0.2 mW). Under illumination, a net photocurrent (<em>I_ph</em>) ≈ 2.7 × 10<sup>−6</sup> A is obtained at −2 V, yielding an optical contrast I_light/I_dark ∼ 10<sup>3</sup>, with a responsivity (<em>R</em>) ≈ 1.33 × 10<sup>−2</sup> A W<sup>−1</sup> and a specific detectivity (<em>D∗</em>) ≈ 1.15 × 10<sup>9</sup> Jones at (−2 V). To interpret the illuminated characteristics, we develop a two-dimensional <em>(2D</em>) drift–diffusion model (Poisson + continuity) including optical generation (parameter <em>powrm,</em> normalized illumination level) and Shockley–Read–Hall (SRH) recombination through interface and grain-boundary traps (total trap density <em>N</em><sub><em>T</em></sub>, with <em>N</em><sub><em>TA</em></sub> and <em>N</em><sub><em>TD</em></sub>). The parametric analysis shows that optical generation sets the photocurrent amplitude, the donor concentration (N<sub>D</sub>) governs forward conduction, and N<sub>T</sub> controls recombination losses, strongly impacting the forward branch and the open-circuit voltage V_oc. No combination of these parameters reproduces the experimental reverse-bias behavior without impact ionization; introducing this mechanism captures the high-field rise and curvature while preserving the forward branch. Using N<sub>D</sub> independently extracted from capacitance–voltage (<em>C–V</em>) measurements (1 MHz) and keeping the other inputs fixed from independent characterizations, the best agreement is obtained for <em>N</em><sub><em>TA</em></sub> = 2.85 × 10<sup>12</sup> cm<sup>−2</sup> and <em>N</em><sub><em>TD</em></sub> = 3.25 × 10<sup>12</sup> cm<sup>−2</sup>, supporting the overall consistency of the <em>2D</em> model and the coupled influence of optical generation, transport, recombination, and impact ionization on the illuminated <em>I–V</em> characteristics. Compared with prior reports on Ag/poly-Si diodes, this work combines systematic dark/illuminated measurements on an Ag/poly-Si/ITO device fabricated on glass with a dedicated 2D drift–diffusion model that incorporates trap-assisted recombination and impact ionization, enabling a physically constrained interpretation of the photoresponse and extracted parameters.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"212 ","pages":"Article 208578"},"PeriodicalIF":3.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146173689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work, the structural and electronic properties of ReSe2-based heterostructures (ReSe2-MoS2, ReSe2-MoSSe, and ReSeS-MoS2) were investigated using density functional theory (DFT). All systems exhibited semiconducting behavior, with ReSe2-MoSSe showing the strongest interlayer coupling and the smallest band gap. Phosphorus doping was introduced to tune their electronic characteristics and carrier transport. Substitutional incorporation of phosphorus at sulfur sites reduced slightly the interlayer spacing, enhanced interlayer and intralayer orbital hybridization among Mo, Re, and S/Se atoms, and altered charge distribution. In ReSe2-MoS2 and ReSe2-MoSSe, Phosphorus incorporation moderately widened the band gap and reduced the carrier effective mass, while preserving semiconducting characteristics. Conversely, P-doped ReSeS-MoS2 exhibited a transition toward semimetallic behavior, characterized by a finite density of states at the Fermi level. These results demonstrate that phosphorus doping effectively modulates band alignment, interlayer interactions, and carrier dynamics, providing a promising strategy for optimizing ReSe2-based heterostructures for nanoelectronic and optoelectronic applications.
{"title":"Electronic structure modulation in phosphorus-doped ReSe2 heterostructures for tunable optoelectronic applications","authors":"Hossein Hojjati, Ebrahim Mohammadi-Manesh, Dariush Souri","doi":"10.1016/j.micrna.2026.208573","DOIUrl":"10.1016/j.micrna.2026.208573","url":null,"abstract":"<div><div>In this work, the structural and electronic properties of ReSe<sub>2</sub>-based heterostructures (ReSe<sub>2</sub>-MoS<sub>2</sub>, ReSe<sub>2</sub>-MoSSe, and ReSeS-MoS<sub>2</sub>) were investigated using density functional theory (DFT). All systems exhibited semiconducting behavior, with ReSe<sub>2</sub>-MoSSe showing the strongest interlayer coupling and the smallest band gap. Phosphorus doping was introduced to tune their electronic characteristics and carrier transport. Substitutional incorporation of phosphorus at sulfur sites reduced slightly the interlayer spacing, enhanced interlayer and intralayer orbital hybridization among Mo, Re, and S/Se atoms, and altered charge distribution. In ReSe<sub>2</sub>-MoS<sub>2</sub> and ReSe<sub>2</sub>-MoSSe, Phosphorus incorporation moderately widened the band gap and reduced the carrier effective mass, while preserving semiconducting characteristics. Conversely, P-doped ReSeS-MoS<sub>2</sub> exhibited a transition toward semimetallic behavior, characterized by a finite density of states at the Fermi level. These results demonstrate that phosphorus doping effectively modulates band alignment, interlayer interactions, and carrier dynamics, providing a promising strategy for optimizing ReSe<sub>2</sub>-based heterostructures for nanoelectronic and optoelectronic applications.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"212 ","pages":"Article 208573"},"PeriodicalIF":3.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146079287","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 : 2026-04-01Epub Date: 2026-01-07DOI: 10.1016/j.micrna.2026.208567
T.F. Cantalice, S.M. Urahata, A.A. Quivy
InAs/GaAs submonolayer quantum dots rely on the vertical alignment of two-dimensional InAs islands separated by thin GaAs layers. These stacks arise from the local strain field generated by the lattice mismatch between the constituent materials. However, experimental observations show that such quantum dots appear irregular and shorter than expected. Indium segregation is particularly strong in the InAs/GaAs system and is suspected to weaken the internal strain field. To confirm this assumption, we simulated the strain in the GaAs matrix surrounding InAs inclusions with the shape of either a full sphere or a thin truncated hemisphere. The results demonstrate that, when the original two-dimensional InAs islands are realistically represented by a thin truncated hemisphere subjected to strong In segregation, the internal strain is indeed much lower than that required to form full stacks, even for distances as short as a few monolayers between inclusions.
{"title":"Weakening of the internal strain field in InAs/GaAs submonolayer quantum dots due to indium segregation","authors":"T.F. Cantalice, S.M. Urahata, A.A. Quivy","doi":"10.1016/j.micrna.2026.208567","DOIUrl":"10.1016/j.micrna.2026.208567","url":null,"abstract":"<div><div>InAs/GaAs submonolayer quantum dots rely on the vertical alignment of two-dimensional InAs islands separated by thin GaAs layers. These stacks arise from the local strain field generated by the lattice mismatch between the constituent materials. However, experimental observations show that such quantum dots appear irregular and shorter than expected. Indium segregation is particularly strong in the InAs/GaAs system and is suspected to weaken the internal strain field. To confirm this assumption, we simulated the strain in the GaAs matrix surrounding InAs inclusions with the shape of either a full sphere or a thin truncated hemisphere. The results demonstrate that, when the original two-dimensional InAs islands are realistically represented by a thin truncated hemisphere subjected to strong In segregation, the internal strain is indeed much lower than that required to form full stacks, even for distances as short as a few monolayers between inclusions.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"212 ","pages":"Article 208567"},"PeriodicalIF":3.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145929327","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 : 2026-04-01Epub Date: 2026-01-14DOI: 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.
{"title":"A numerical investigation on the performance of D/E-mode GaN HEMTs with nitride stress films","authors":"Xing Wang , Yifei Wang , Guanyu Wang , Chunyu Zhou , Bo Ye , Song Shi","doi":"10.1016/j.micrna.2026.208572","DOIUrl":"10.1016/j.micrna.2026.208572","url":null,"abstract":"<div><div>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.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"212 ","pages":"Article 208572"},"PeriodicalIF":3.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145981364","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 : 2026-04-01Epub Date: 2026-01-20DOI: 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。
{"title":"Tunable properties of PtSe2/ZrS2 heterojunction and Te-doped PtSe2/ZrS2 heterojunction","authors":"Hangqing Wu, Lu Yang, Hang Su, Liqun Wu","doi":"10.1016/j.micrna.2026.208579","DOIUrl":"10.1016/j.micrna.2026.208579","url":null,"abstract":"<div><div>This study systematically investigates the synergistic modulation effects of Te doping and perpendicular external electric fields on the electronic structure and optical response of PtSe<sub>2</sub>/ZrS<sub>2</sub> two-dimensional heterostructures using first-principles density functional theory (DFT). Three representative stable configurations were selected for comparison: A1 (undoped PtSe<sub>2</sub>/ZrS<sub>2</sub>), B1 (Te substituting S atoms in the ZrS<sub>2</sub> layer), and C1 (Te substituting Se atoms in the PtSe<sub>2</sub> 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 PtSe<sub>2</sub>/ZrS<sub>2</sub> heterostructures, laying a foundation for structural design and performance optimization of tunable two-dimensional optoelectronic devices.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"212 ","pages":"Article 208579"},"PeriodicalIF":3.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146026227","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}
The increasing demand for high-efficiency Photovoltaic (PV) materials necessitates the development of cost-effective semiconductor alloys. Group 4 alloys emerged as a potential breakthrough material for the next generation PV technology because they enable precise bandgap engineering and lattice matching, which mitigates defect states and reduces non-radiative recombination losses. The structure incorporates Cu2O/Si1-x-yGeySnx/WS2/FTO, where Si1-x-yGeySnx is incorporated as an absorber layer. The device's performance has been rigorously evaluated through spectral response analysis, electrical and frequency response characterization, noise power spectral density analysis, and electric field distribution studies. The performance of the PV structure is analyzed for various Ge compositions for the absorber layer Si1-x-yGeySnx (y = 0.25, 0.30,0.35, 0.40). A solar cell utilizing a Si1-x-yGeySnx alloy with a Ge content of 25 % yields a power conversion efficiency of 23.7 %. This device exhibits an open-circuit voltage (Voc) of 0.97 V, a short-circuit current density (Jsc) of 38 mA/cm2, and a fill factor (FF) of 84.1 %. These performance metrics underscore the potential of Group 4 SiGeSn-based materials in advancing PV technologies and outcomes of this work are expected to contribute toward the advancement of high-efficiency Group 4 alloy-based solar cell technologies.
{"title":"SiGeSn alloy solar cells: Noise, recombination, and performance insights","authors":"Nikita , Jaspinder Kaur , Preeti Verma , Ajay Kumar Sharma , Jaya Madan , Rahul Pandey , Rikmantra Basu","doi":"10.1016/j.micrna.2026.208568","DOIUrl":"10.1016/j.micrna.2026.208568","url":null,"abstract":"<div><div>The increasing demand for high-efficiency Photovoltaic (PV) materials necessitates the development of cost-effective semiconductor alloys. Group 4 alloys emerged as a potential breakthrough material for the next generation PV technology because they enable precise bandgap engineering and lattice matching, which mitigates defect states and reduces non-radiative recombination losses. The structure incorporates Cu<sub>2</sub>O/Si<sub>1-x-y</sub>Ge<sub>y</sub>Sn<sub>x</sub>/WS<sub>2</sub>/FTO, where Si<sub>1-x-y</sub>Ge<sub>y</sub>Sn<sub>x</sub> is incorporated as an absorber layer. The device's performance has been rigorously evaluated through spectral response analysis, electrical and frequency response characterization, noise power spectral density analysis, and electric field distribution studies. The performance of the PV structure is analyzed for various Ge compositions for the absorber layer Si<sub>1-x-y</sub>Ge<sub>y</sub>Sn<sub>x</sub> (y = 0.25, 0.30,0.35, 0.40). A solar cell utilizing a Si<sub>1-x-y</sub>Ge<sub>y</sub>Sn<sub>x</sub> alloy with a Ge content of 25 % yields a power conversion efficiency of 23.7 %. This device exhibits an open-circuit voltage (Voc) of 0.97 V, a short-circuit current density (Jsc) of 38 mA/cm<sup>2</sup>, and a fill factor (FF) of 84.1 %. These performance metrics underscore the potential of Group 4 SiGeSn-based materials in advancing PV technologies and outcomes of this work are expected to contribute toward the advancement of high-efficiency Group 4 alloy-based solar cell technologies.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"212 ","pages":"Article 208568"},"PeriodicalIF":3.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146026241","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 : 2026-04-01Epub Date: 2026-01-05DOI: 10.1016/j.micrna.2026.208563
Van Thanh Pham , Nguyen Hai Pham , Van Tan Tran , Oscar Martínez Sacristán , Jyh-Shen Tsay , Viet Tuyen Nguyen , Thu Hang Bui , Trung Kien Do , Quang Loc Do , Cong Doanh Sai , Thi Ha Tran
In this study, we present a fast and facile self-resistive heating method to fabricate copper oxide (CuO) nanowires using copper (Cu) substrates. The effect of growth temperature and time were thoroughly investigated through both experiment and simulations. X-ray diffraction (XRD) and Raman spectroscopy confirmed the successful formation of highly crystalline CuO phase. Scanning electron microscopy (SEM) images demonstrated that the nanowires were uniform in size and at high density, indicating an efficient synthesis process. Additional analyses were conducted to further elucidate a thermodynamic mechanism of the growth of CuO nanowires. Our broad experimental and simulation data on synthesis parameters provides a detailed view on the growth of the nanowires and explains the efficient growth of aligned CuO nanowires synthesized by resistive heating method.
{"title":"Efficient synthesis and growth mechanisms of CuO nanowires via self-resistive heating","authors":"Van Thanh Pham , Nguyen Hai Pham , Van Tan Tran , Oscar Martínez Sacristán , Jyh-Shen Tsay , Viet Tuyen Nguyen , Thu Hang Bui , Trung Kien Do , Quang Loc Do , Cong Doanh Sai , Thi Ha Tran","doi":"10.1016/j.micrna.2026.208563","DOIUrl":"10.1016/j.micrna.2026.208563","url":null,"abstract":"<div><div>In this study, we present a fast and facile self-resistive heating method to fabricate copper oxide (CuO) nanowires using copper (Cu) substrates. The effect of growth temperature and time were thoroughly investigated through both experiment and simulations. X-ray diffraction (XRD) and Raman spectroscopy confirmed the successful formation of highly crystalline CuO phase. Scanning electron microscopy (SEM) images demonstrated that the nanowires were uniform in size and at high density, indicating an efficient synthesis process. Additional analyses were conducted to further elucidate a thermodynamic mechanism of the growth of CuO nanowires. Our broad experimental and simulation data on synthesis parameters provides a detailed view on the growth of the nanowires and explains the efficient growth of aligned CuO nanowires synthesized by resistive heating method.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"212 ","pages":"Article 208563"},"PeriodicalIF":3.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145981294","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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