Herein, films of barium antimonides (BaSb) are fabricated by a thermal deposition technique under a vacuum pressure of 10−5 mbar. BaSb films exhibit orthorhombic lattice. Over a wide range of scans, the films are mostly stoichiometric, displaying atomic contents of 50.17 and 49.83 at% for Ba and Sb, respectively. Morphological analyses of these films show the growth of large grains with sizes ranging from 1.64 to 4.14 μm. Dynamic electrical measurements on Ag/BaSb/Ag films are conducted in the frequency domain of 0.01–1.80 GHz. The films display features of voltage‐controlled negative capacitance source (VCNC) and resonance–antiresonance peaks at a critical frequency of 1.64 GHz. Lorentz models spectral analyses on these peaks indicate that they correspond to a high‐frequency capacitance value of 2.8 nF, a density of oscillators of 4 × 1010 cm−3, and a scattering time constant of τ = 100 ns. Additionally, Ag/BaSb/Ag films show a wide variety in the cutoff frequency spectra, making them suitable for high‐frequency applications. The cutoff frequency varies from 2.6 GHz to 1.0 THz as driving frequency increases from 1.0 to 1.64 GHz. The features of VCNC sources, resonance–antiresonance behavior, and high cutoff frequency make BaSb thin films promising for thin‐film transistors and 6 G technology applications.
{"title":"Characterization and High‐Frequency Applications of Barium Antimonide Thin Films for Voltage‐Controlled Negative Capacitance and 6G Technology","authors":"Atef Fayez Qasrawi","doi":"10.1002/pssa.202400449","DOIUrl":"https://doi.org/10.1002/pssa.202400449","url":null,"abstract":"Herein, films of barium antimonides (BaSb) are fabricated by a thermal deposition technique under a vacuum pressure of 10<jats:sup>−5</jats:sup> mbar. BaSb films exhibit orthorhombic lattice. Over a wide range of scans, the films are mostly stoichiometric, displaying atomic contents of 50.17 and 49.83 at% for Ba and Sb, respectively. Morphological analyses of these films show the growth of large grains with sizes ranging from 1.64 to 4.14 μm. Dynamic electrical measurements on Ag/BaSb/Ag films are conducted in the frequency domain of 0.01–1.80 GHz. The films display features of voltage‐controlled negative capacitance source (VCNC) and resonance–antiresonance peaks at a critical frequency of 1.64 GHz. Lorentz models spectral analyses on these peaks indicate that they correspond to a high‐frequency capacitance value of 2.8 nF, a density of oscillators of 4 × 10<jats:sup>10</jats:sup> cm<jats:sup>−3</jats:sup>, and a scattering time constant of τ = 100 ns. Additionally, Ag/BaSb/Ag films show a wide variety in the cutoff frequency spectra, making them suitable for high‐frequency applications. The cutoff frequency varies from 2.6 GHz to 1.0 THz as driving frequency increases from 1.0 to 1.64 GHz. The features of VCNC sources, resonance–antiresonance behavior, and high cutoff frequency make BaSb thin films promising for thin‐film transistors and 6 G technology applications.","PeriodicalId":20074,"journal":{"name":"Physica Status Solidi A-applications and Materials Science","volume":"43 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141880866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abdul Kuddus, Tomomasa Sato, Kojun Yokoyama, Hajime Shirai
The spatial and size distributions of titanium diisopropoxide bisacetylacetonate [(C5H7O2)2[(CH3)2CHO]2, also known as Ti(acac)2(OiPr)2] mist, diluted in CH3OH, are investigated in a tubular furnace using atmospheric‐pressure mist chemical vapor deposition (mist CVD). The focus is on the deposition of amorphous (a)‐TiO2 films with tubular furnace temperature and mesh bias as variables. When the furnace temperature reaches 350 °C, the number density of mist particles increases without significant changes in their size distribution, leading to a higher film deposition rate. Further, the deposition rate and average size of the mist particles with lower adhesion coefficient decrease with increasing spatial distance from the furnace inlet. Furthermore, applying a mesh bias results in an increase in the maximum number density of mist particles with a narrower size distribution; however, the overall film deposition rate decreases. These variations are attributed to the chemical reactivity of the mist precursors produced by pyrolysis and mesh bias. The fine mist precursors, which are strongly charged, coordinate with CH3OH and CHO groups through solvation, enhancing their chemical stability and lifetime. This process yields a dense and rigid a‐TiO2 network, improving the junction properties at the a‐TiO2/c‐Si interface.
{"title":"Spatial and Size Distributions of Ti(C5H7O2)2[(CH3)2CHO]2 Mist Particles in a Tubular Furnace for Conformal and Uniform Deposition of Amorphous TiO2 Thin Films","authors":"Abdul Kuddus, Tomomasa Sato, Kojun Yokoyama, Hajime Shirai","doi":"10.1002/pssa.202400383","DOIUrl":"https://doi.org/10.1002/pssa.202400383","url":null,"abstract":"The spatial and size distributions of titanium diisopropoxide bisacetylacetonate [(C<jats:sub>5</jats:sub>H<jats:sub>7</jats:sub>O<jats:sub>2</jats:sub>)<jats:sub>2</jats:sub>[(CH<jats:sub>3</jats:sub>)<jats:sub>2</jats:sub>CHO]<jats:sub>2</jats:sub>, also known as Ti(acac)<jats:sub>2</jats:sub>(OiPr)<jats:sub>2</jats:sub>] mist, diluted in CH<jats:sub>3</jats:sub>OH, are investigated in a tubular furnace using atmospheric‐pressure mist chemical vapor deposition (mist CVD). The focus is on the deposition of amorphous (a)‐TiO<jats:sub>2</jats:sub> films with tubular furnace temperature and mesh bias as variables. When the furnace temperature reaches 350 °C, the number density of mist particles increases without significant changes in their size distribution, leading to a higher film deposition rate. Further, the deposition rate and average size of the mist particles with lower adhesion coefficient decrease with increasing spatial distance from the furnace inlet. Furthermore, applying a mesh bias results in an increase in the maximum number density of mist particles with a narrower size distribution; however, the overall film deposition rate decreases. These variations are attributed to the chemical reactivity of the mist precursors produced by pyrolysis and mesh bias. The fine mist precursors, which are strongly charged, coordinate with CH<jats:sub>3</jats:sub>OH and CHO groups through solvation, enhancing their chemical stability and lifetime. This process yields a dense and rigid a‐TiO<jats:sub>2</jats:sub> network, improving the junction properties at the a‐TiO<jats:sub>2</jats:sub>/c‐Si interface.","PeriodicalId":20074,"journal":{"name":"Physica Status Solidi A-applications and Materials Science","volume":"75 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141880867","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kaio Jonathas Alencar Gurgel, Francisco Enilton Alves Nogueira, Daniel Barros de Freitas, João Paulo Costa do Nascimento, Tallison Oliveira Abreu, Paulo Maria de Oliveira Silva, Felipe Felix do Carmo, Marcelo Antonio Santos da Silva, Ronaldo Santos da Silva, Antonio Sergio Bezerra Sombra
This study presents experimental investigations and numerical simulations of the microwave (MW) dielectric and evaluation of the electrical properties in the radiofrequency region (RF). The ceramic matrix Li2LaNbTiO7 (LLNT) is obtained through the solid‐state reaction method. The synthesis of LLNT is confirmed using the X‐ray diffraction technique. In the complex impedance spectroscopy study, permittivity (ε′r) and loss tangent (tanδ) values are analyzed at room temperature. The study of the conductivity spectrum at different temperatures demonstrates that the conduction process is thermally activated, presenting a value of 0.65 eV for the activation energy. Numerical simulations are employed to evaluate the behavior of the LLNT matrix as dielectric resonator antennas (DRA), whereas this ceramics demonstrated a reflection coefficient of less than −10 dB at the resonant frequency, achieving a gain of 3.71 dBi, a bandwidth of 144 MHz and a radiation efficiency greater than 97%. The results indicate that the LLNT matrix would be a promising candidate for RF and MW operating devices.
{"title":"Improved Temperature Sensitivity of the Microwave and Radiofrequency Properties of the Ceramic Matrix Li2LaNbTiO7","authors":"Kaio Jonathas Alencar Gurgel, Francisco Enilton Alves Nogueira, Daniel Barros de Freitas, João Paulo Costa do Nascimento, Tallison Oliveira Abreu, Paulo Maria de Oliveira Silva, Felipe Felix do Carmo, Marcelo Antonio Santos da Silva, Ronaldo Santos da Silva, Antonio Sergio Bezerra Sombra","doi":"10.1002/pssa.202400480","DOIUrl":"https://doi.org/10.1002/pssa.202400480","url":null,"abstract":"This study presents experimental investigations and numerical simulations of the microwave (MW) dielectric and evaluation of the electrical properties in the radiofrequency region (RF). The ceramic matrix Li<jats:sub>2</jats:sub>LaNbTiO<jats:sub>7</jats:sub> (LLNT) is obtained through the solid‐state reaction method. The synthesis of LLNT is confirmed using the X‐ray diffraction technique. In the complex impedance spectroscopy study, permittivity (<jats:italic>ε</jats:italic>′<jats:sub>r</jats:sub>) and loss tangent (tan<jats:italic>δ</jats:italic>) values are analyzed at room temperature. The study of the conductivity spectrum at different temperatures demonstrates that the conduction process is thermally activated, presenting a value of 0.65 eV for the activation energy. Numerical simulations are employed to evaluate the behavior of the LLNT matrix as dielectric resonator antennas (DRA), whereas this ceramics demonstrated a reflection coefficient of less than −10 dB at the resonant frequency, achieving a gain of 3.71 dBi, a bandwidth of 144 MHz and a radiation efficiency greater than 97%. The results indicate that the LLNT matrix would be a promising candidate for RF and MW operating devices.","PeriodicalId":20074,"journal":{"name":"Physica Status Solidi A-applications and Materials Science","volume":"16 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141880864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study explores the application of pillar nanostructures in organic solar cells (OSCs). The aluminum pillar nanostructures (AlPNSs) are fabricated on an active layer surface comprising of a blend poly(3‐hexylthiophene‐2,5‐diyl) and [6,6]‐phenyl C61 butyric acid methyl ester using nanoimprinting. Aluminum back electrodes are formed, resulting in AlPNSs with an imprinted pattern height of 60 ± 6 nm and a pitch of 212 ± 49 nm. Atomic force microscope images and current density versus voltage curves are obtained for the fabricated devices, both with and without AlPNSs. The results indicate a solar cell efficiency increase of 15.16% in the AlPNS OSCs compared to the reference cells. To investigate the role of AlPNSs in the enhancement, impedance spectroscopy, incident photon‐to‐current efficiency, UV–Vis reflection spectroscopy, and finite‐difference time‐domain simulations are performed for the both devices. The results demonstrate that the combination of propagating surface plasmon resonance and light‐trapping properties due to AlPNSs significantly enhances the overall optical performance. This research provides new insights into the potential of imprinted nanostructures for enhancing OSC performance, including their plasmonic and optical characteristics.
{"title":"Influence of Aluminum Pillar Nanostructures on Thin‐Film Organic Solar Cells","authors":"Apichat Phengdaam, Nonthanan Sitpathom, Minghui Hong, Kazunari Shinbo, Keizo Kato, Akira Baba","doi":"10.1002/pssa.202400221","DOIUrl":"https://doi.org/10.1002/pssa.202400221","url":null,"abstract":"This study explores the application of pillar nanostructures in organic solar cells (OSCs). The aluminum pillar nanostructures (AlPNSs) are fabricated on an active layer surface comprising of a blend poly(3‐hexylthiophene‐2,5‐diyl) and [6,6]‐phenyl C61 butyric acid methyl ester using nanoimprinting. Aluminum back electrodes are formed, resulting in AlPNSs with an imprinted pattern height of 60 ± 6 nm and a pitch of 212 ± 49 nm. Atomic force microscope images and current density versus voltage curves are obtained for the fabricated devices, both with and without AlPNSs. The results indicate a solar cell efficiency increase of 15.16% in the AlPNS OSCs compared to the reference cells. To investigate the role of AlPNSs in the enhancement, impedance spectroscopy, incident photon‐to‐current efficiency, UV–Vis reflection spectroscopy, and finite‐difference time‐domain simulations are performed for the both devices. The results demonstrate that the combination of propagating surface plasmon resonance and light‐trapping properties due to AlPNSs significantly enhances the overall optical performance. This research provides new insights into the potential of imprinted nanostructures for enhancing OSC performance, including their plasmonic and optical characteristics.","PeriodicalId":20074,"journal":{"name":"Physica Status Solidi A-applications and Materials Science","volume":"215 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141880930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Reported depth profiles of hydrogen in plasma‐exposed n‐Si samples can be fitted with a simple model of hydrogen transport by negative and neutral species (H− and H0) accompanied by a reversible formation of hydrogen–donor pairs (HD) and by an irreversible production of mobile dimers H2A—in particular by a bulk pairing reaction of the H− and H0 species. Contrary to a complicated behavior of hydrogen found in p‐Si (with multiple independent states for positive ions and passivated boron), the situation in n‐Si appears to be much simpler as only single states for H−, H0, and HD are sufficient for profile reproduction. The parameters deduced from the profiles are the diffusivity of H−, the characteristic electron concentration marking equal contributions of H− and H0 into hydrogen transport, and the diffusivity of H2A dimers (in the available temperature range 120–225 °C).
{"title":"Properties of Hydrogen Species in n‐Type Silicon Deduced from In‐Diffusion Profiles","authors":"Vladimir V. Voronkov, Robert Falster","doi":"10.1002/pssa.202400360","DOIUrl":"https://doi.org/10.1002/pssa.202400360","url":null,"abstract":"Reported depth profiles of hydrogen in plasma‐exposed n‐Si samples can be fitted with a simple model of hydrogen transport by negative and neutral species (H<jats:sup>−</jats:sup> and H<jats:sup>0</jats:sup>) accompanied by a reversible formation of hydrogen–donor pairs (HD) and by an irreversible production of mobile dimers H<jats:sub>2A</jats:sub>—in particular by a bulk pairing reaction of the H<jats:sup>−</jats:sup> and H<jats:sup>0</jats:sup> species. Contrary to a complicated behavior of hydrogen found in p‐Si (with multiple independent states for positive ions and passivated boron), the situation in n‐Si appears to be much simpler as only single states for H<jats:sup>−</jats:sup>, H<jats:sup>0</jats:sup>, and HD are sufficient for profile reproduction. The parameters deduced from the profiles are the diffusivity of H<jats:sup>−</jats:sup>, the characteristic electron concentration marking equal contributions of H<jats:sup>−</jats:sup> and H<jats:sup>0</jats:sup> into hydrogen transport, and the diffusivity of H<jats:sub>2A</jats:sub> dimers (in the available temperature range 120–225 °C).","PeriodicalId":20074,"journal":{"name":"Physica Status Solidi A-applications and Materials Science","volume":"22 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141864678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ancy Michel, Binola K. Jebalin I. V., S. Angen Franklin, Sylvia Juliet Rani, Angelin Delighta A., D. Nirmal
A quasi‐vertical gallium nitride (GaN) fin field effect transistor (FinFET) is designed and analyzed to assess the performance of electrical parameters. The device is deployed on a silicon carbide (SiC) substrate and analyzed using technology computer‐aided design (TCAD). The donor concentration in the critical regions is identified as a significant limiting factor for FinFET electrical properties. Hence, the influence of channel and drift layer doping concentrations (Nd) on performance characteristics is investigated in this work. The electrical characteristics such as threshold voltage, ION/IOFF ratio, subthreshold swing (SS), specific ON‐resistance, and breakdown voltage (VBV) are evaluated for various doping profiles. The doping profile with channel and drift layer concentration of 4 × 1015 cm−3 for a 300 nm fin width and 1 μm thick drift layer exhibits normally OFF behavior with a threshold voltage (Vt) of 1.5 V. It also demonstrates a VBV of 139 V. The corresponding doping profile reveals a low SS of 61 mV dec−1, which is comparable to other similar power devices. This demonstrates the significant potential of the device for medium‐power switching applications.
{"title":"Influence of Doping Engineering in 1 μm Drift Layer Quasi‐Vertical Fin Field‐Effect Transistor for Achieving >139 V Breakdown Voltage","authors":"Ancy Michel, Binola K. Jebalin I. V., S. Angen Franklin, Sylvia Juliet Rani, Angelin Delighta A., D. Nirmal","doi":"10.1002/pssa.202400137","DOIUrl":"https://doi.org/10.1002/pssa.202400137","url":null,"abstract":"A quasi‐vertical gallium nitride (GaN) fin field effect transistor (FinFET) is designed and analyzed to assess the performance of electrical parameters. The device is deployed on a silicon carbide (SiC) substrate and analyzed using technology computer‐aided design (TCAD). The donor concentration in the critical regions is identified as a significant limiting factor for FinFET electrical properties. Hence, the influence of channel and drift layer doping concentrations (Nd) on performance characteristics is investigated in this work. The electrical characteristics such as threshold voltage, <jats:italic>I</jats:italic><jats:sub>ON</jats:sub>/<jats:italic>I</jats:italic><jats:sub>OFF</jats:sub> ratio, subthreshold swing (SS), specific ON‐resistance, and breakdown voltage (<jats:italic>V</jats:italic><jats:sub>BV</jats:sub>) are evaluated for various doping profiles. The doping profile with channel and drift layer concentration of 4 × 10<jats:sup>15 </jats:sup>cm<jats:sup>−3</jats:sup> for a 300 nm fin width and 1 μm thick drift layer exhibits normally OFF behavior with a threshold voltage (<jats:italic>V</jats:italic><jats:sub>t</jats:sub>) of 1.5 V. It also demonstrates a <jats:italic>V</jats:italic><jats:sub>BV</jats:sub> of 139 V. The corresponding doping profile reveals a low SS of 61 mV dec<jats:sup>−1</jats:sup>, which is comparable to other similar power devices. This demonstrates the significant potential of the device for medium‐power switching applications.","PeriodicalId":20074,"journal":{"name":"Physica Status Solidi A-applications and Materials Science","volume":"33 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141771419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Elisabeth R. M. van Haaren, Vincent Ornelis, Yvonne L. J. Vissers, Marc B. I. Lobbes, Kasper Eersels, Lee H. Bouwman
Upon surgical removal of solid tumors in patients with breast cancer, the sentinel lymph nodes are mostly concomitantly removed as this is the first site to which tumor cells metastasize. To identify the sentinel lymph nodes, superparamagnetic iron oxide (SPIO) particles can be employed, a method that has several advantages over the classical tracer with radioisotopes. However, one downside of SPIO particles is the formation of artifacts on magnetic resonance imaging (MRI) of the breast. In a previous study, we investigated if lowering the dose of these particles from 2 to 1 mL would prevent the occurrence of these artifacts. In a study of 14 patients, radiologists do not observe any artifacts on the full‐field digital mammography and contrast‐enhanced mammography images, contrary to breast MRI images, in which case artifacts are observed on all images. Hence, lowering the dose from 2 to 1 mL SPIO particles did not change the outcome of the breast MRI images. In this article, based on these results, we discuss the origins of these artifacts from a mathematical and physical point of view.
乳腺癌患者在手术切除实体瘤时，大多会同时切除前哨淋巴结，因为这是肿瘤细胞转移的第一个部位。为了识别前哨淋巴结，可以使用超顺磁性氧化铁（SPIO）粒子，这种方法与传统的放射性同位素示踪法相比有许多优点。然而，SPIO 粒子的一个缺点是会在乳腺磁共振成像（MRI）中产生伪影。在之前的一项研究中，我们研究了将这些粒子的剂量从 2 毫升降低到 1 毫升是否能避免这些伪影的出现。在对 14 名患者进行的研究中，放射科医生在全视野数字乳腺 X 射线照相术和对比增强乳腺 X 射线照相术图像上未观察到任何伪影，而在乳腺核磁共振成像图像上则相反，所有图像上都能观察到伪影。因此，将 SPIO 粒子的剂量从 2 毫升降低到 1 毫升并不会改变乳腺核磁共振成像的结果。在本文中，我们将根据这些结果，从数学和物理的角度讨论这些伪影的起源。
{"title":"Use of Superparamagnetic Iron Oxide Particles in Sentinel Node Biopsy—Evaluation of Its Effects on Breast MRI, Full‐Field Digital Mammography, and Contrast‐Enhanced Mammography","authors":"Elisabeth R. M. van Haaren, Vincent Ornelis, Yvonne L. J. Vissers, Marc B. I. Lobbes, Kasper Eersels, Lee H. Bouwman","doi":"10.1002/pssa.202400370","DOIUrl":"https://doi.org/10.1002/pssa.202400370","url":null,"abstract":"Upon surgical removal of solid tumors in patients with breast cancer, the sentinel lymph nodes are mostly concomitantly removed as this is the first site to which tumor cells metastasize. To identify the sentinel lymph nodes, superparamagnetic iron oxide (SPIO) particles can be employed, a method that has several advantages over the classical tracer with radioisotopes. However, one downside of SPIO particles is the formation of artifacts on magnetic resonance imaging (MRI) of the breast. In a previous study, we investigated if lowering the dose of these particles from 2 to 1 mL would prevent the occurrence of these artifacts. In a study of 14 patients, radiologists do not observe any artifacts on the full‐field digital mammography and contrast‐enhanced mammography images, contrary to breast MRI images, in which case artifacts are observed on all images. Hence, lowering the dose from 2 to 1 mL SPIO particles did not change the outcome of the breast MRI images. In this article, based on these results, we discuss the origins of these artifacts from a mathematical and physical point of view.","PeriodicalId":20074,"journal":{"name":"Physica Status Solidi A-applications and Materials Science","volume":"20 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141771420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shimul Kanti Nath, Ibrahim Turan, Léonard Desvignes, Ludovic Largeau, Olivia Mauguin, Marc Túnica, Michele Amato, Charles Renard, Géraldine Hallais, Dominique Débarre, Francesca Chiodi
Superconductivity in ultradoped Si1−xGex:B epilayers is demonstrated by nanosecond laser doping, which allows introducing substitutional B concentrations well above the solubility limit and up to 7 at%. A Ge fraction x ranging from 0 to 0.21 is incorporated in Si:B: 1) through a precursor gas, by gas immersion laser doping; 2) by ion implantation, followed by nanosecond laser annealing; and 3) by ultrahigh‐vacuum‐chemical vapor deposition growth of a thin Ge layer, followed by nanosecond laser annealing. The 30 and 75 nm‐thick Si1−xGex:B epilayers display superconducting critical temperatures Tc tuned by B and Ge between 0 and 0.6 K. Within Bardeen Cooper Schrieffer (BCS) weak‐coupling theory, Tc evolves exponentially with both the density of states and the electron–phonon potential. While B doping affects both, through the increase of the carrier density and the tensile strain, Ge incorporation allows addressing independently the lattice deformation influence on superconductivity. To estimate the lattice parameter modulation with B and Ge, Vegard's law is validated for the ternary SiGeB bulk alloy by density functional theory calculations. Its validity is furthermore confirmed experimentally by X‐ray diffraction. A global linear dependence of Tc versus lattice parameter, common for both Si:B and Si1−xGex:B, with δTc/Tc ≈ 50% for δa/a ≈1%, is highlighted.
通过纳秒激光掺杂，超掺杂 Si1-xGex:B 外延层中的超导性得到了证实，这种掺杂允许引入远高于溶解极限的替代 B 浓度，最高可达 7%。在 Si:B 中掺入了 0 至 0.21 的 Ge 分数 x：1）通过前驱气体，采用气体浸入激光掺杂法；2）采用离子注入法，然后进行纳秒激光退火；3）采用超高真空化学气相沉积法生长一个薄的 Ge 层，然后进行纳秒激光退火。根据巴丁-库珀-施里弗（BCS）弱耦合理论，超导临界温度 Tc 随状态密度和电子-声子电势呈指数变化。掺杂 B 会通过增加载流子密度和拉伸应变影响这两方面，而掺杂 Ge 则可以单独解决晶格变形对超导性的影响。为了估算晶格参数随 B 和 Ge 的变化而变化的情况，我们通过密度泛函理论计算对 SiGeB 三元体合金的 Vegard 定律进行了验证。此外，还通过 X 射线衍射实验进一步证实了该定律的有效性。Tc 与晶格参数的总体线性关系在 Si:B 和 Si1-xGex:B 中都很常见，当 δa/a ≈1% 时，δTc/Tc≈50%。
{"title":"Tuning Superconductivity in Nanosecond Laser‐Annealed Boron‐Doped Si1–xGex Epilayers","authors":"Shimul Kanti Nath, Ibrahim Turan, Léonard Desvignes, Ludovic Largeau, Olivia Mauguin, Marc Túnica, Michele Amato, Charles Renard, Géraldine Hallais, Dominique Débarre, Francesca Chiodi","doi":"10.1002/pssa.202400313","DOIUrl":"https://doi.org/10.1002/pssa.202400313","url":null,"abstract":"Superconductivity in ultradoped Si<jats:sub>1−<jats:italic>x</jats:italic></jats:sub>Ge<jats:sub><jats:italic>x</jats:italic></jats:sub>:B epilayers is demonstrated by nanosecond laser doping, which allows introducing substitutional B concentrations well above the solubility limit and up to 7 at%. A Ge fraction <jats:italic>x</jats:italic> ranging from 0 to 0.21 is incorporated in Si:B: 1) through a precursor gas, by gas immersion laser doping; 2) by ion implantation, followed by nanosecond laser annealing; and 3) by ultrahigh‐vacuum‐chemical vapor deposition growth of a thin Ge layer, followed by nanosecond laser annealing. The 30 and 75 nm‐thick Si<jats:sub>1−<jats:italic>x</jats:italic></jats:sub>Ge<jats:sub><jats:italic>x</jats:italic></jats:sub>:B epilayers display superconducting critical temperatures <jats:italic>T</jats:italic><jats:sub>c</jats:sub> tuned by B and Ge between 0 and 0.6 K. Within Bardeen Cooper Schrieffer (BCS) weak‐coupling theory, <jats:italic>T</jats:italic><jats:sub>c</jats:sub> evolves exponentially with both the density of states and the electron–phonon potential. While B doping affects both, through the increase of the carrier density and the tensile strain, Ge incorporation allows addressing independently the lattice deformation influence on superconductivity. To estimate the lattice parameter modulation with B and Ge, Vegard's law is validated for the ternary SiGeB bulk alloy by density functional theory calculations. Its validity is furthermore confirmed experimentally by X‐ray diffraction. A global linear dependence of <jats:italic>T</jats:italic><jats:sub>c</jats:sub> versus lattice parameter, common for both Si:B and Si<jats:sub>1−<jats:italic>x</jats:italic></jats:sub>Ge<jats:sub><jats:italic>x</jats:italic></jats:sub>:B, with <jats:italic>δ</jats:italic><jats:italic>T</jats:italic><jats:sub>c</jats:sub>/<jats:italic>T</jats:italic><jats:sub>c</jats:sub> ≈ 50% for <jats:italic>δ</jats:italic><jats:italic>a</jats:italic>/<jats:italic>a</jats:italic> ≈1%, is highlighted.","PeriodicalId":20074,"journal":{"name":"Physica Status Solidi A-applications and Materials Science","volume":"16 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141771383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Clara Rittmann, Ella S. Supik, Marion Drießen, Friedemann D. Heinz, Yves P. Botchak Mouafi, Florian Schindler, Charlotte Weiss, Martin C. Schubert, Stefan Janz
Aiming for highly efficient solar cells based on wafers with a low carbon footprint, silicon (Si) EpiWafers are grown epitaxially on reusable, highly doped Si substrates with a stack of porous Si layers (PorSi) for detachment. A state‐of‐the‐art p‐type Si EpiWafer exhibiting a minority charge carrier lifetime of up to 2.2 ms detected at an excess charge carrier density of ≈1 × 1015 cm−3 by photoluminescence (PL) imaging is presented. This translates to a predicted solar cell efficiency of 25.6%, calculated by efficiency limiting bulk recombination analysis (ELBA), and corresponds to losses of less than 1%abs compared to the theoretical limit of the investigated solar cell concept. A detailed loss analysis shows that the major remaining quality limitations are structural defects, specifically stacking faults (SFs). Therefore, the recombination activity of isolated SFs in epitaxially grown reference (EpiRef) wafers on polished substrates without a PorSi is assessed by highly resolved μPL mappings. The recombination activity rises with the number of dislocations within an SF as demonstrated by a comparison to microscope images. When using highly doped substrates, as currently required for EpiWafer fabrication, EpiRef wafers show more SFs exhibiting additionally a higher number of dislocations than SFs in EpiRef wafers on moderately doped substrates.
为了实现基于低碳足迹硅片的高效太阳能电池，在可重复使用的高掺杂硅衬底上外延生长了硅 (Si) EpiWafer，并堆叠了多孔硅层 (PorSi)，用于分离。通过光致发光（PL）成像，在过剩电荷载流子密度≈1 × 1015 cm-3时检测到的少数电荷载流子寿命可达 2.2 ms。通过效率限制体重组分析（ELBA）计算，预测太阳能电池的效率为 25.6%，与所研究的太阳能电池概念的理论极限相比，损耗小于 1%abs。详细的损耗分析表明，剩余的主要质量限制是结构缺陷，特别是堆叠缺陷（SF）。因此，通过高分辨率的 μPL 贴图评估了在抛光基底上外延生长的参考（EpiRef）晶片中孤立 SF 的重组活动。通过与显微镜图像的对比，可以看出重组活动随着 SF 内位错数量的增加而增加。当使用目前 EpiWafer 制造所需的高掺杂基底时，与使用中等掺杂基底的 EpiRef 晶圆中的 SF 相比，EpiRef 晶圆中有更多 SF 显示出更多的位错。
{"title":"Recombination Activity of Crystal Defects in Epitaxially Grown Silicon Wafers for Highly Efficient Solar Cells","authors":"Clara Rittmann, Ella S. Supik, Marion Drießen, Friedemann D. Heinz, Yves P. Botchak Mouafi, Florian Schindler, Charlotte Weiss, Martin C. Schubert, Stefan Janz","doi":"10.1002/pssa.202400226","DOIUrl":"https://doi.org/10.1002/pssa.202400226","url":null,"abstract":"Aiming for highly efficient solar cells based on wafers with a low carbon footprint, silicon (Si) EpiWafers are grown epitaxially on reusable, highly doped Si substrates with a stack of porous Si layers (PorSi) for detachment. A state‐of‐the‐art p‐type Si EpiWafer exhibiting a minority charge carrier lifetime of up to 2.2 ms detected at an excess charge carrier density of ≈1 × 10<jats:sup>15</jats:sup> cm<jats:sup>−3</jats:sup> by photoluminescence (PL) imaging is presented. This translates to a predicted solar cell efficiency of 25.6%, calculated by efficiency limiting bulk recombination analysis (ELBA), and corresponds to losses of less than 1%<jats:sub>abs</jats:sub> compared to the theoretical limit of the investigated solar cell concept. A detailed loss analysis shows that the major remaining quality limitations are structural defects, specifically stacking faults (SFs). Therefore, the recombination activity of isolated SFs in epitaxially grown reference (EpiRef) wafers on polished substrates without a PorSi is assessed by highly resolved μPL mappings. The recombination activity rises with the number of dislocations within an SF as demonstrated by a comparison to microscope images. When using highly doped substrates, as currently required for EpiWafer fabrication, EpiRef wafers show more SFs exhibiting additionally a higher number of dislocations than SFs in EpiRef wafers on moderately doped substrates.","PeriodicalId":20074,"journal":{"name":"Physica Status Solidi A-applications and Materials Science","volume":"16 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141771422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
John McElearney, Kevin Grossklaus, T. Pan Menasuta, Thomas Vandervelde
Variable‐angle spectroscopic ellipsometry is used to determine the room temperature complex refractive index of molecular beam epitaxy grown GaSb1−xBix films with x ≤ 4.25% over a spectral range of 0.47–6.2 eV. By correlating to critical points in the extinction coefficient k, the energies of several interband transitions are extracted as functions of Bi content. The observed change in the fundamental bandgap energy (E0, −36.5 meV per %Bi) agrees well with previously published values; however, the samples examined here show a much more rapid increase in the spin‐orbit splitting energy (Δ0, +30.1 meV per Bi) than previous calculations have predicted. As in the related GaAsBi, the energy of transitions involving the top of the valence band are observed to have a much stronger dependence on Bi content than those that do not, suggesting the valence band maximum is most sensitive to Bi alloying. Finally, the effects of surface droplets on both the complex refractive index and the critical point energies are examined.
变角光谱椭偏仪用于测定分子束外延生长的 x ≤ 4.25% 的 GaSb1-xBix 薄膜在 0.47-6.2 eV 光谱范围内的室温复合折射率。通过与消光系数 k 的临界点相关联，提取了若干带间跃迁的能量，作为铋含量的函数。观察到的基本带隙能（E0，-36.5 meV/%Bi）的变化与之前公布的值十分吻合；然而，这里研究的样品显示自旋轨道分裂能（Δ0，+30.1 meV/%Bi）的增加比之前的计算结果预测的要快得多。正如在相关的砷化镓铋中观察到的那样，涉及价带顶部的跃迁能量对铋含量的依赖性比不涉及价带顶部的跃迁能量的依赖性要强得多，这表明价带最大值对铋合金化最为敏感。最后，研究了表面液滴对复合折射率和临界点能量的影响。
{"title":"Determination of the Complex Refractive Index of GaSb1−xBix by Variable‐Angle Spectroscopic Ellipsometry","authors":"John McElearney, Kevin Grossklaus, T. Pan Menasuta, Thomas Vandervelde","doi":"10.1002/pssa.202400017","DOIUrl":"https://doi.org/10.1002/pssa.202400017","url":null,"abstract":"Variable‐angle spectroscopic ellipsometry is used to determine the room temperature complex refractive index of molecular beam epitaxy grown GaSb<jats:sub>1−<jats:italic>x</jats:italic></jats:sub>Bi<jats:sub><jats:italic>x</jats:italic></jats:sub> films with <jats:italic>x</jats:italic> ≤ 4.25% over a spectral range of 0.47–6.2 eV. By correlating to critical points in the extinction coefficient <jats:italic>k</jats:italic>, the energies of several interband transitions are extracted as functions of Bi content. The observed change in the fundamental bandgap energy (<jats:italic>E</jats:italic><jats:sub>0</jats:sub>, −36.5 meV per %Bi) agrees well with previously published values; however, the samples examined here show a much more rapid increase in the spin‐orbit splitting energy (Δ<jats:sub>0</jats:sub>, +30.1 meV per Bi) than previous calculations have predicted. As in the related GaAsBi, the energy of transitions involving the top of the valence band are observed to have a much stronger dependence on Bi content than those that do not, suggesting the valence band maximum is most sensitive to Bi alloying. Finally, the effects of surface droplets on both the complex refractive index and the critical point energies are examined.","PeriodicalId":20074,"journal":{"name":"Physica Status Solidi A-applications and Materials Science","volume":"16 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141771424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：