In this study, the tensile properties of SiCf/Ti60 composites under hot isostatic pressing (HIP) and 600 °C/100h states were investigated. The properties of thermal exposure SiCf/Ti60 composites were reduced by about 34 MPa compared to the properties of HIP composites with good thermal stability. The results show that SiCf/Ti60 composites have good matrix and interfacial thermal stability. The average grain size of matrix α-Ti in both states was 3.4-3.6 μm, the texture of α-Ti was <0001>//AD and <10-10>//AD, and the polar densities ranged from 6.9 to 7.4 to 2.7-3.1, respectively. The thickness of the interfacial reaction layer in both states was about 0.38-0.43 μm, the interfacial thickness increased slowly, and the silicon content fraction at the interface remains virtually unchanged. The interfacial silicide volume fraction is similar. About 58.2 MPa reduced the residual compressive stress of SiC fibers after thermal exposure. In summary, SiCf/Ti60 composites exhibit excellent microstructure, mechanical properties, and thermal stability, enabling long-term operation in a 600 °C vacuum environment.
{"title":"Effect of long-term thermal exposure at 600°C on the tensile properties of SiCf/Ti60 composites","authors":"Zhicong Gan, Yumin Wang, Lina Yang, Qiuyue Jia, Mushi Li, Yuming Zhang, Xu Kong, Rui Yang","doi":"10.1016/j.vacuum.2026.115157","DOIUrl":"10.1016/j.vacuum.2026.115157","url":null,"abstract":"<div><div>In this study, the tensile properties of SiC<sub>f</sub>/Ti60 composites under hot isostatic pressing (HIP) and 600 °C/100h states were investigated. The properties of thermal exposure SiC<sub>f</sub>/Ti60 composites were reduced by about 34 MPa compared to the properties of HIP composites with good thermal stability. The results show that SiC<sub>f</sub>/Ti60 composites have good matrix and interfacial thermal stability. The average grain size of matrix α-Ti in both states was 3.4-3.6 μm, the texture of α-Ti was <0001>//AD and <10-10>//AD, and the polar densities ranged from 6.9 to 7.4 to 2.7-3.1, respectively. The thickness of the interfacial reaction layer in both states was about 0.38-0.43 μm, the interfacial thickness increased slowly, and the silicon content fraction at the interface remains virtually unchanged. The interfacial silicide volume fraction is similar. About 58.2 MPa reduced the residual compressive stress of SiC fibers after thermal exposure. In summary, SiC<sub>f</sub>/Ti60 composites exhibit excellent microstructure, mechanical properties, and thermal stability, enabling long-term operation in a 600 °C vacuum environment.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"247 ","pages":"Article 115157"},"PeriodicalIF":3.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146174089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In response to the critical material requirements in the field of long-wavelength infrared detection, this study systematically investigates the effect of growth temperature on the material quality and interfacial properties of long-wavelength superlattices. By growing InAs/GaSb type-II superlattice samples at different temperatures (360°C–460 °C), a variety of characterization techniques including atomic force microscopy, X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy were employed to systematically analyze the influence of temperature on surface morphology, crystal quality, strain state, and interfacial chemical stability. The results indicate that the sample grown at 380 °C exhibits clear atomic step-flow morphology, low root-mean-square roughness (0.262 nm), sharp interfaces, and excellent period uniformity, demonstrating that this temperature represents the optimal condition for achieving high-quality layered growth of superlattices. This study provides a reliable process window and theoretical foundation for the high-quality superlattice materials required for high-performance long-wavelength infrared detectors.
{"title":"Growth temperature optimization for high-quality InAs/GaSb Type-II superlattices grown by MBE towards high-performance long-wavelength infrared detection","authors":"Rong Yan, Yuhao Chen, Zhenfei Xing, Jing Yu, Bingfeng Liu, Weiqiang Chen, Lidan Lu, Lianqing Zhu","doi":"10.1016/j.vacuum.2026.115083","DOIUrl":"10.1016/j.vacuum.2026.115083","url":null,"abstract":"<div><div>In response to the critical material requirements in the field of long-wavelength infrared detection, this study systematically investigates the effect of growth temperature on the material quality and interfacial properties of long-wavelength superlattices. By growing InAs/GaSb type-II superlattice samples at different temperatures (360°C–460 °C), a variety of characterization techniques including atomic force microscopy, X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy were employed to systematically analyze the influence of temperature on surface morphology, crystal quality, strain state, and interfacial chemical stability. The results indicate that the sample grown at 380 °C exhibits clear atomic step-flow morphology, low root-mean-square roughness (0.262 nm), sharp interfaces, and excellent period uniformity, demonstrating that this temperature represents the optimal condition for achieving high-quality layered growth of superlattices. This study provides a reliable process window and theoretical foundation for the high-quality superlattice materials required for high-performance long-wavelength infrared detectors.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"247 ","pages":"Article 115083"},"PeriodicalIF":3.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146025510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","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.vacuum.2026.115125
Xiao Xi , Xuxu Liu , Wei Jin , Jipeng Zhu , Hai Jin , Xiaoqiu Ye , Changan Chen
In this study, a 13.56 MHz radio frequency power supply was used to generate an external solenoid inductively coupled plasma source. An ion energy mass spectrometer equipped with a Bessel box and quadrupole mass filter was employed to investigate the characteristics of ion in expansion region. The ion species, concentration and their energy distributions with different working gases, including deuterium, nitrogen and their mixtures, have been analyzed by adjusting the gas flow rate or relative concentration over a wide parametric range. The results give the evolution of deuterium series D+/D2+/D3+, nitrogen series N+/N2+/N2D+, and the ammonia series ND+/ND2+/ND3+/ND4+. The ion energy distribution of D3+, N2+ and ND4+ display multi-peak distributions, indicating sheath voltage modulation and frequent collisional production in gas phase. The signal intensities and peak energies of these ions show distinct trends with respect to the gas flow rate. The reaction processes been given to illustrate the transformation path within and between different ion series. The reactions can be divided into three stages: ionization regime, intermediate regime and recombination regime, depending on the overall gas flow rate. And the N2D+ is an effective media during molecular assisted recombination stage. These results benefit plasma processing and chemical synthesis.
{"title":"Distribution of ion energy and concentration in the expansion region of radio-frequency inductive coupled plasmas with deuterium and deuterium-nitrogen mixtures","authors":"Xiao Xi , Xuxu Liu , Wei Jin , Jipeng Zhu , Hai Jin , Xiaoqiu Ye , Changan Chen","doi":"10.1016/j.vacuum.2026.115125","DOIUrl":"10.1016/j.vacuum.2026.115125","url":null,"abstract":"<div><div>In this study, a 13.56 MHz radio frequency power supply was used to generate an external solenoid inductively coupled plasma source. An ion energy mass spectrometer equipped with a Bessel box and quadrupole mass filter was employed to investigate the characteristics of ion in expansion region. The ion species, concentration and their energy distributions with different working gases, including deuterium, nitrogen and their mixtures, have been analyzed by adjusting the gas flow rate or relative concentration over a wide parametric range. The results give the evolution of deuterium series D<sup>+</sup>/D<sub>2</sub><sup>+</sup>/D<sub>3</sub><sup>+</sup>, nitrogen series N<sup>+</sup>/N<sub>2</sub><sup>+</sup>/N<sub>2</sub>D<sup>+</sup>, and the ammonia series ND<sup>+</sup>/ND<sub>2</sub><sup>+</sup>/ND<sub>3</sub><sup>+</sup>/ND<sub>4</sub><sup>+</sup>. The ion energy distribution of D<sub>3</sub><sup>+</sup>, N<sub>2</sub><sup>+</sup> and ND<sub>4</sub><sup>+</sup> display multi-peak distributions, indicating sheath voltage modulation and frequent collisional production in gas phase. The signal intensities and peak energies of these ions show distinct trends with respect to the gas flow rate. The reaction processes been given to illustrate the transformation path within and between different ion series. The reactions can be divided into three stages: ionization regime, intermediate regime and recombination regime, depending on the overall gas flow rate. And the N<sub>2</sub>D<sup>+</sup> is an effective media during molecular assisted recombination stage. These results benefit plasma processing and chemical synthesis.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"247 ","pages":"Article 115125"},"PeriodicalIF":3.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146025511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-04-01Epub Date: 2026-01-19DOI: 10.1016/j.vacuum.2026.115103
Yanping Lv , Ziyi Qin , Menghe Liu , Jun Zhang , Ming Yang , Hao Wu
Tin(II) sulfide (SnS) has exhibited promising characteristics for photovoltaic applications, yet the efficiency of SnS thin-film photovoltaics is still constrained by carrier transport bottlenecks at interfaces and defect-mediated recombination near the buffer/absorber heterojunction. This study systematically investigates the influence of seed-layer-induced crystallization engineering on the CdS buffer layer to optimize SnS device performance. XRD and cross-sectional TEM confirm the transition to a polycrystalline CdS structure, while TPV and EIS analyses reveal a significant enhancement in recombination resistance and carrier lifetime. Moreover, the seed-layer-induced crystallization leads to a favorable downshift of the CdS conduction band minimum, facilitating electron injection from SnS into CdS and thereby improving charge collection. As a result, the optimized FTO/CdS/SnS/Ag solar cells achieve a notable 83 % increase in PCE (from 1.16 % to 2.12 %), underscoring the critical importance of crystallinity control and interface engineering in developing high-performance SnS-based photovoltaics.
{"title":"Seed-layer-assisted crystallization engineering of CdS for high-performance CdS/SnS heterojunction solar cells","authors":"Yanping Lv , Ziyi Qin , Menghe Liu , Jun Zhang , Ming Yang , Hao Wu","doi":"10.1016/j.vacuum.2026.115103","DOIUrl":"10.1016/j.vacuum.2026.115103","url":null,"abstract":"<div><div>Tin(II) sulfide (SnS) has exhibited promising characteristics for photovoltaic applications, yet the efficiency of SnS thin-film photovoltaics is still constrained by carrier transport bottlenecks at interfaces and defect-mediated recombination near the buffer/absorber heterojunction. This study systematically investigates the influence of seed-layer-induced crystallization engineering on the CdS buffer layer to optimize SnS device performance. XRD and cross-sectional TEM confirm the transition to a polycrystalline CdS structure, while TPV and EIS analyses reveal a significant enhancement in recombination resistance and carrier lifetime. Moreover, the seed-layer-induced crystallization leads to a favorable downshift of the CdS conduction band minimum, facilitating electron injection from SnS into CdS and thereby improving charge collection. As a result, the optimized FTO/CdS/SnS/Ag solar cells achieve a notable 83 % increase in PCE (from 1.16 % to 2.12 %), underscoring the critical importance of crystallinity control and interface engineering in developing high-performance SnS-based photovoltaics.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"247 ","pages":"Article 115103"},"PeriodicalIF":3.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146026012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","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.vacuum.2026.115129
Zhuofu Wei , Xiwen Hu , Shiyu Niu , Yuxin Wang , Zhongliang Liu , Zhenwen Yang , Ying Wang
To obtain the high-strength joint of zirconium alloy and stainless steel for nuclear applications, this study utilized a Ti interlayer for diffusion bonding of Zr-3 alloy and 304L stainless steel. Direct diffusion bonding resulted in the formation of numerous brittle intermetallic compounds, including Zr2(Fe, Ni) and Zr(Fe, Cr)2. The introduction of the Ti interlayer eliminated these phases, and the typical interfacial reaction layer of the joints was Zr-3/(Ti, Zr)/Ti/NiTi/TiFe/TiCr2/(Fe, Cr)/304L. The diffusion layer at the Ti/304L interface was identified as the key factor governing the joint's mechanical properties. Within this layer, TiFe and NiTi phases formed preferentially, followed by TiCr2 and (Fe, Cr) phases. Higher bonding temperatures and longer holding times significantly promoted the interdiffusion of Ti with Fe and Cr from the 304L steel. This enrichment of brittle TiFe and TiCr2 phases at the interface consequently degraded the joint properties. The joint achieved a peak shear strength of 247 MPa under the parameters of 760 °C/60 min/10 MPa, representing a 115 % increase compared to the direct diffusion-bonded joint. The fracture was primarily initiated in the brittle phases, such as TiFe and TiCr2, within the Ti/304L diffusion layer.
{"title":"Enhancement of interfacial structure and mechanical properties of Zr-3 alloy and 304L stainless steel diffusion bonded joint via Ti interlayer introduction","authors":"Zhuofu Wei , Xiwen Hu , Shiyu Niu , Yuxin Wang , Zhongliang Liu , Zhenwen Yang , Ying Wang","doi":"10.1016/j.vacuum.2026.115129","DOIUrl":"10.1016/j.vacuum.2026.115129","url":null,"abstract":"<div><div>To obtain the high-strength joint of zirconium alloy and stainless steel for nuclear applications, this study utilized a Ti interlayer for diffusion bonding of Zr-3 alloy and 304L stainless steel. Direct diffusion bonding resulted in the formation of numerous brittle intermetallic compounds, including Zr<sub>2</sub>(Fe, Ni) and Zr(Fe, Cr)<sub>2</sub>. The introduction of the Ti interlayer eliminated these phases, and the typical interfacial reaction layer of the joints was Zr-3/(Ti, Zr)/Ti/NiTi/TiFe/TiCr<sub>2</sub>/(Fe, Cr)/304L. The diffusion layer at the Ti/304L interface was identified as the key factor governing the joint's mechanical properties. Within this layer, TiFe and NiTi phases formed preferentially, followed by TiCr<sub>2</sub> and (Fe, Cr) phases. Higher bonding temperatures and longer holding times significantly promoted the interdiffusion of Ti with Fe and Cr from the 304L steel. This enrichment of brittle TiFe and TiCr<sub>2</sub> phases at the interface consequently degraded the joint properties. The joint achieved a peak shear strength of 247 MPa under the parameters of 760 °C/60 min/10 MPa, representing a 115 % increase compared to the direct diffusion-bonded joint. The fracture was primarily initiated in the brittle phases, such as TiFe and TiCr<sub>2</sub>, within the Ti/304L diffusion layer.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"247 ","pages":"Article 115129"},"PeriodicalIF":3.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-04-01Epub Date: 2026-01-19DOI: 10.1016/j.vacuum.2026.115120
Yao Tao , Xia Chen , Qiang Chen , Bin Chen
Magnesium alloys are promising candidates for lightweight engineering applications. However, the presence of Ag impedes the formation of long-period stacking ordered (LPSO) phases in Mg-Gd-Ag alloys, thereby restricting the optimization of their mechanical properties. While Zn doping is well-documented to facilitate LPSO phase formation in Mg-RE-TM systems, the underlying mechanism by which Zn modulates this process in Ag-containing Mg-Gd alloys remains elusive. Herein, we investigate the LPSO phases in Mg140Gd16TM12 (TM = Ag, Zn) alloys with varying Zn/Ag ratios via HAADF-STEM and first-principles calculations, clarifying their thermodynamic stability, mechanical properties, and electronic structures. Experimental results confirm the formation of 14H and 18R LPSO phases, with Zn substituting Ag to facilitate LPSO nucleation. First-principles calculations show that all Zn-containing phases exhibit negative formation enthalpies, with increasing Zn content enhancing thermodynamic stability (Mg140Gd16Zn12 being the most stable). Zn doping reduces Young's and shear moduli but improves ductility, as indicated by the increasing Pugh ratio (1.49–1.55) and Poisson's ratio (0.226–0.233). Electronic structure analysis reveals deep hybridization of Mg-p, Gd-d, and Zn-d orbitals in the −2.5∼2.0 eV range; Zn enrichment weakens Ag's bridging effect, making Zn-d orbitals dominant in bonding. This work provides insights for optimizing Mg-Gd-Ag alloy performance via composition regulation.
{"title":"Elucidating long period stacking ordered phases in Mg-Gd-Ag alloys with Zn doping: A synergistic experimental and first-principles study","authors":"Yao Tao , Xia Chen , Qiang Chen , Bin Chen","doi":"10.1016/j.vacuum.2026.115120","DOIUrl":"10.1016/j.vacuum.2026.115120","url":null,"abstract":"<div><div>Magnesium alloys are promising candidates for lightweight engineering applications. However, the presence of Ag impedes the formation of long-period stacking ordered (LPSO) phases in Mg-Gd-Ag alloys, thereby restricting the optimization of their mechanical properties. While Zn doping is well-documented to facilitate LPSO phase formation in Mg-RE-TM systems, the underlying mechanism by which Zn modulates this process in Ag-containing Mg-Gd alloys remains elusive. Herein, we investigate the LPSO phases in Mg<sub>140</sub>Gd<sub>16</sub>TM<sub>12</sub> (TM = Ag, Zn) alloys with varying Zn/Ag ratios via HAADF-STEM and first-principles calculations, clarifying their thermodynamic stability, mechanical properties, and electronic structures. Experimental results confirm the formation of 14H and 18R LPSO phases, with Zn substituting Ag to facilitate LPSO nucleation. First-principles calculations show that all Zn-containing phases exhibit negative formation enthalpies, with increasing Zn content enhancing thermodynamic stability (Mg<sub>140</sub>Gd<sub>16</sub>Zn<sub>12</sub> being the most stable). Zn doping reduces Young's and shear moduli but improves ductility, as indicated by the increasing Pugh ratio (1.49–1.55) and Poisson's ratio (0.226–0.233). Electronic structure analysis reveals deep hybridization of Mg-p, Gd-d, and Zn-d orbitals in the −2.5∼2.0 eV range; Zn enrichment weakens Ag's bridging effect, making Zn-d orbitals dominant in bonding. This work provides insights for optimizing Mg-Gd-Ag alloy performance via composition regulation.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"247 ","pages":"Article 115120"},"PeriodicalIF":3.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146025495","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","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.vacuum.2026.115124
S. Ghalab , Mansour Aouassa , A.K. Aladim , Saud A. Algarni , Majed Alharbi , Mohammed Ibrahim , K.M.A. Saron , Mohammed Bouabdellaoui , Isabelle Berbezier
In this work, we grow and investigate CMOS-compatible Ge quantum dots (Ge QDs) integrated into metal–oxide–semiconductor (MOS) photodetectors, with a focus on their electrical transport and photocurrent response. Crystalline Ge QDs with an average diameter of ≈5.8 nm, hemispherical shape, and a high density (∼5 × 1012 cm−2) are formed by solid-state dewetting of a 1 nm amorphous Ge film grown by molecular beam epitaxy (MBE) on SiO2/Si, subsequently capped with a 45 nm SiO2 layer, and finally converted into MOS Ge-QD photodetectors by depositing transparent AuPd pads. Temperature-dependent current–voltage and capacitance–voltage measurements, complemented by photocurrent analysis, reveal the formation of a Schottky-like MOS photodetector exhibiting a rectification ratio close to 102 and a low dark current. Charge transport is governed by thermionic emission assisted by Fowler–Nordheim tunneling, with the embedded Ge QDs acting as efficient charge-relay centers in the oxide, facilitating carrier injection and reducing the threshold voltage without degrading the capacitive behavior of the structure. Under illumination, the Ge-QD–based MOS photodetectors show a pronounced enhancement of photosensitivity, particularly in the visible spectral range, consistent with strong quantum confinement in the QDs. These results demonstrate that MBE-grown Ge QDs obtained by solid-state dewetting provide a promising platform for the realization of CMOS-compatible, low-power, high-performance optoelectronic devices, especially photodetectors and, more broadly, quantum-dot–engineered solar-cell architectures.
{"title":"CMOS-compatible MBE-grown germanium quantum dots for high-performance photodetectors and solar cells","authors":"S. Ghalab , Mansour Aouassa , A.K. Aladim , Saud A. Algarni , Majed Alharbi , Mohammed Ibrahim , K.M.A. Saron , Mohammed Bouabdellaoui , Isabelle Berbezier","doi":"10.1016/j.vacuum.2026.115124","DOIUrl":"10.1016/j.vacuum.2026.115124","url":null,"abstract":"<div><div>In this work, we grow and investigate CMOS-compatible Ge quantum dots (Ge QDs) integrated into metal–oxide–semiconductor (MOS) photodetectors, with a focus on their electrical transport and photocurrent response. Crystalline Ge QDs with an average diameter of ≈5.8 nm, hemispherical shape, and a high density (∼5 × 10<sup>12</sup> cm<sup>−2</sup>) are formed by solid-state dewetting of a 1 nm amorphous Ge film grown by molecular beam epitaxy (MBE) on SiO<sub>2</sub>/Si, subsequently capped with a 45 nm SiO<sub>2</sub> layer, and finally converted into MOS Ge-QD photodetectors by depositing transparent AuPd pads. Temperature-dependent current–voltage and capacitance–voltage measurements, complemented by photocurrent analysis, reveal the formation of a Schottky-like MOS photodetector exhibiting a rectification ratio close to 10<sup>2</sup> and a low dark current. Charge transport is governed by thermionic emission assisted by Fowler–Nordheim tunneling, with the embedded Ge QDs acting as efficient charge-relay centers in the oxide, facilitating carrier injection and reducing the threshold voltage without degrading the capacitive behavior of the structure. Under illumination, the Ge-QD–based MOS photodetectors show a pronounced enhancement of photosensitivity, particularly in the visible spectral range, consistent with strong quantum confinement in the QDs. These results demonstrate that MBE-grown Ge QDs obtained by solid-state dewetting provide a promising platform for the realization of CMOS-compatible, low-power, high-performance optoelectronic devices, especially photodetectors and, more broadly, quantum-dot–engineered solar-cell architectures.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"247 ","pages":"Article 115124"},"PeriodicalIF":3.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146025500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","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.vacuum.2026.115123
Dongdong Chen , Zan Long , Sirong Zhu , Huaxin Liang , Yuan Teng , Cunji Pu , Jikang Yan , Yanqing Lai , Jianhong Yi
The structure of the interfacial layer is important for evaluating the reliability of an electronic package. Herein, we comprehensively investigated the changes in morphology and thickness of intermetallic compounds interlayer during aging, the diffusion of elements during the reflow soldering and isothermal aging, as well as the phase structural and crystallographic relationships among β-Sn, Cu6Sn5, and Cu3Sn phases. After aging, Cu6Sn5/β-Sn interface exhibited special crystallographic relationship, while the angle between and was 174.1°. Cu6Sn5/Cu3Sn interface showed special crystallographic relationship, while the angle between and was 58.7°. The growth patterns of Cu6Sn5 and Cu3Sn phases during isothermal aging were investigated further based on the interface orientation relationship. This study reported the growth of the interface IMCs layer via the interfacial structure of Cu6Sn5/β-Sn, Cu6Sn5/Cu3Sn, and Cu3Sn/Cu, which further improves the orientation relationship of interface phases. Meanwhile, this work provides a valuable basis for improving the reliability of solder service.
{"title":"Research on the phase interface structure and orientation relationship of the intermetallic compounds layer in Sn-3.0Ag-0.5Cu/Cu joints during isothermal aging","authors":"Dongdong Chen , Zan Long , Sirong Zhu , Huaxin Liang , Yuan Teng , Cunji Pu , Jikang Yan , Yanqing Lai , Jianhong Yi","doi":"10.1016/j.vacuum.2026.115123","DOIUrl":"10.1016/j.vacuum.2026.115123","url":null,"abstract":"<div><div>The structure of the interfacial layer is important for evaluating the reliability of an electronic package. Herein, we comprehensively investigated the changes in morphology and thickness of intermetallic compounds interlayer during aging, the diffusion of elements during the reflow soldering and isothermal aging, as well as the phase structural and crystallographic relationships among β-Sn, Cu<sub>6</sub>Sn<sub>5</sub>, and Cu<sub>3</sub>Sn phases. After aging, Cu<sub>6</sub>Sn<sub>5</sub><strong>/</strong>β-Sn interface exhibited special <span><math><mrow><msub><mrow><mo>[</mo><mn>010</mn><mo>]</mo></mrow><mrow><mi>β</mi><mo>−</mo><mi>S</mi><mi>n</mi></mrow></msub><mo>/</mo><mo>/</mo><msub><mrow><mo>[</mo><mn>210</mn><mo>]</mo></mrow><mrow><mi>C</mi><msub><mi>u</mi><mn>6</mn></msub><mi>S</mi><msub><mi>n</mi><mn>5</mn></msub></mrow></msub></mrow></math></span> crystallographic relationship, while the angle between <span><math><mrow><msub><mrow><mo>(</mo><mrow><mover><mn>1</mn><mo>‾</mo></mover><mn>01</mn></mrow><mo>)</mo></mrow><mrow><mi>β</mi><mo>−</mo><mi>S</mi><mi>n</mi></mrow></msub></mrow></math></span> and <span><math><mrow><msub><mrow><mo>(</mo><mrow><mover><mn>1</mn><mo>‾</mo></mover><mn>21</mn></mrow><mo>)</mo></mrow><mrow><mi>C</mi><msub><mi>u</mi><mn>6</mn></msub><mi>S</mi><msub><mi>n</mi><mn>5</mn></msub></mrow></msub></mrow></math></span> was 174.1°. Cu<sub>6</sub>Sn<sub>5</sub><strong>/</strong>Cu<sub>3</sub>Sn interface showed special <span><math><mrow><msub><mrow><mo>[</mo><mn>111</mn><mo>]</mo></mrow><mrow><mi>C</mi><msub><mi>u</mi><mn>6</mn></msub><mi>S</mi><mi>n</mi><mn>5</mn></mrow></msub><mo>/</mo><mo>/</mo><msub><mrow><mo>[</mo><mn>001</mn><mo>]</mo></mrow><mrow><mi>C</mi><msub><mi>u</mi><mn>3</mn></msub><mi>S</mi><mi>n</mi></mrow></msub></mrow></math></span> crystallographic relationship, while the angle between <span><math><mrow><msub><mrow><mo>(</mo><mrow><mn>3</mn><mover><mn>1</mn><mo>‾</mo></mover><mover><mn>2</mn><mo>‾</mo></mover></mrow><mo>)</mo></mrow><mrow><mi>C</mi><msub><mi>u</mi><mn>6</mn></msub><mi>S</mi><msub><mi>n</mi><mn>5</mn></msub></mrow></msub></mrow></math></span> and <span><math><mrow><msub><mrow><mo>(</mo><mrow><mn>2</mn><mover><mn>1</mn><mo>‾</mo></mover><mn>0</mn></mrow><mo>)</mo></mrow><mrow><mi>C</mi><msub><mi>u</mi><mn>3</mn></msub><mi>S</mi><mi>n</mi></mrow></msub></mrow></math></span> was 58.7°. The growth patterns of Cu<sub>6</sub>Sn<sub>5</sub> and Cu<sub>3</sub>Sn phases during isothermal aging were investigated further based on the interface orientation relationship. This study reported the growth of the interface IMCs layer via the interfacial structure of Cu<sub>6</sub>Sn<sub>5</sub><strong>/</strong>β-Sn, Cu<sub>6</sub>Sn<sub>5</sub><strong>/</strong>Cu<sub>3</sub>Sn, and Cu<sub>3</sub>Sn/Cu, which further improves the orientation relationship of interface phases. Meanwhile, this work provides a valuable basis for improving the reliability of solder service.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"247 ","pages":"Article 115123"},"PeriodicalIF":3.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146025498","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","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.vacuum.2026.115102
Guoheng Yu , Detian Li , Huzhong Zhang , Weijun Huang , Changkun Dong , Zhenhua Xi , Gang Li , Zhangyi Zhong , Weidong Kang
Carbon nanotubes (CNTs) are a type of field emission cathode material with broad application potential. Compared with hot filament cathodes, CNTs cathodes possess advantages such as low operating temperature and energy efficiency. In this article, a CNTs electron emitter is integrated into an ionization gauge featuring a straight electron path. A series of tests were performed on the CNTs cathode and the prototype gauge. The optimal operating potential of the prototype gauge was determined through simulations and experiments. The prototype achieved a sensitivity of 0.317 Pa−1 in argon and 0.240 Pa−1 in nitrogen. This prototype gauge exhibits good linearity in the range from 10−6 Pa to 10−3 Pa in argon and nitrogen, while its sensitivity fluctuations are 1.17 % and 3.2 %, and within half an hour, the sensitivity fluctuations in the two gases are 1.6 % and 2.2 % respectively. Under simulated normal operating conditions, the repeatability is less than 3 %. This novel developed ionization gauge has simultaneously achieved high sensitivity and good stability. This study provides insights for the application of CNTs cathodes in the ionization gauges.
碳纳米管是一种具有广泛应用潜力的场发射阴极材料。与热丝阴极相比，CNTs阴极具有工作温度低、能效高等优点。在本文中，将碳纳米管电子发射器集成到具有直电子路径的电离计中。对碳纳米管阴极和原型压力表进行了一系列测试。通过仿真和实验，确定了原型仪表的最佳工作电位。样品在氩气和氮气中的灵敏度分别为0.317 Pa−1和0.240 Pa−1。在10−6 Pa ~ 10−3 Pa的氩气和氮气环境中，样品表具有良好的线性关系，灵敏度波动幅度分别为1.17%和3.2%，半小时内，两种气体的灵敏度波动幅度分别为1.6%和2.2%。在模拟正常工作条件下，重复性小于3%。这种新型电离计具有高灵敏度和良好的稳定性。本研究为碳纳米管阴极在电离计中的应用提供了新的思路。
{"title":"A carbon nanotubes cathode ionization gauge with a straight path of electrons","authors":"Guoheng Yu , Detian Li , Huzhong Zhang , Weijun Huang , Changkun Dong , Zhenhua Xi , Gang Li , Zhangyi Zhong , Weidong Kang","doi":"10.1016/j.vacuum.2026.115102","DOIUrl":"10.1016/j.vacuum.2026.115102","url":null,"abstract":"<div><div>Carbon nanotubes (CNTs) are a type of field emission cathode material with broad application potential. Compared with hot filament cathodes, CNTs cathodes possess advantages such as low operating temperature and energy efficiency. In this article, a CNTs electron emitter is integrated into an ionization gauge featuring a straight electron path. A series of tests were performed on the CNTs cathode and the prototype gauge. The optimal operating potential of the prototype gauge was determined through simulations and experiments. The prototype achieved a sensitivity of 0.317 Pa<sup>−</sup><sup>1</sup> in argon and 0.240 Pa<sup>−</sup><sup>1</sup> in nitrogen. This prototype gauge exhibits good linearity in the range from 10<sup>−6</sup> Pa to 10<sup>−3</sup> Pa in argon and nitrogen, while its sensitivity fluctuations are 1.17 % and 3.2 %, and within half an hour, the sensitivity fluctuations in the two gases are 1.6 % and 2.2 % respectively. Under simulated normal operating conditions, the repeatability is less than 3 %. This novel developed ionization gauge has simultaneously achieved high sensitivity and good stability. This study provides insights for the application of CNTs cathodes in the ionization gauges.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"247 ","pages":"Article 115102"},"PeriodicalIF":3.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146026014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-04-01Epub Date: 2026-01-31DOI: 10.1016/j.vacuum.2026.115150
Bohang Yang , Jie Yu , Chenxiang Jin , Ling Zhang , Huihui Wang , Shengzhi Hao
A novel preparation technique of block cathode used for high current pulsed electron beam (HCPEB) emission was essayed. Through the sedimentation of short carbon fibers (SCF) of length 6 mm and adhesion of phenol formaldehyde resin (PFR) of concentration from 6 to 24 wt%, the discrete SCF could be integrated randomly and constituted a desirable structure. The microstructure of cathode was investigated by using X-ray microscopy (XRM) and scanning electron microscopy (SEM). The results showed that a stacked network of SCF was formed homogenously without the bundling phenomena. The carbonized PFR was found at the intersections of SCF. With the PFR of 24 wt%, the severe agglomeration was noticed with an appearance of spheres. The density of cathode increased with the content of SCF and PFR, as well as its capacity of structure maintenance. Contrarily, the resistance rate and evacuation speed were ruined by the density of block cathode. Considering the working requirements, the optimized parameter was selected as the SCF of 6 g and PFR of 12 wt%. The cathode was tested by the HCPEB emission experiment and exhibited satisfactory performance, including the spot size, energy uniformity, emission stability and long-term durability performance.
{"title":"Preparation of block cathode through sedimentation process for high current pulsed electron beam emission","authors":"Bohang Yang , Jie Yu , Chenxiang Jin , Ling Zhang , Huihui Wang , Shengzhi Hao","doi":"10.1016/j.vacuum.2026.115150","DOIUrl":"10.1016/j.vacuum.2026.115150","url":null,"abstract":"<div><div>A novel preparation technique of block cathode used for high current pulsed electron beam (HCPEB) emission was essayed. Through the sedimentation of short carbon fibers (SCF) of length 6 mm and adhesion of phenol formaldehyde resin (PFR) of concentration from 6 to 24 wt%, the discrete SCF could be integrated randomly and constituted a desirable structure. The microstructure of cathode was investigated by using X-ray microscopy (XRM) and scanning electron microscopy (SEM). The results showed that a stacked network of SCF was formed homogenously without the bundling phenomena. The carbonized PFR was found at the intersections of SCF. With the PFR of 24 wt%, the severe agglomeration was noticed with an appearance of spheres. The density of cathode increased with the content of SCF and PFR, as well as its capacity of structure maintenance. Contrarily, the resistance rate and evacuation speed were ruined by the density of block cathode. Considering the working requirements, the optimized parameter was selected as the SCF of 6 g and PFR of 12 wt%. The cathode was tested by the HCPEB emission experiment and exhibited satisfactory performance, including the spot size, energy uniformity, emission stability and long-term durability performance.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"247 ","pages":"Article 115150"},"PeriodicalIF":3.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146174071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号