In this study, the authors investigate the erosive effects of iodine plasma on molybdenum. By exposing molybdenum samples to three different test cases of iodine vapor, iodine plasma, and argon plasma, the plasma enhancement of erosion was characterized. A roughly exponential behavior with respect to temperature was found in iodine plasma at hollow cathode conditions and erosion rates as high as 70.1 ± 7.7 μm/h. Despite an oxygen content of <1%, evidence of oxidation was found in all test cases. Behavior consistent with preferential oxidation based on grain orientation was found in the iodine test cases.
{"title":"Molybdenum erosion in iodine plasma at hollow cathode conditions","authors":"James D. Rogers, R. Branam","doi":"10.1116/6.0003367","DOIUrl":"https://doi.org/10.1116/6.0003367","url":null,"abstract":"In this study, the authors investigate the erosive effects of iodine plasma on molybdenum. By exposing molybdenum samples to three different test cases of iodine vapor, iodine plasma, and argon plasma, the plasma enhancement of erosion was characterized. A roughly exponential behavior with respect to temperature was found in iodine plasma at hollow cathode conditions and erosion rates as high as 70.1 ± 7.7 μm/h. Despite an oxygen content of <1%, evidence of oxidation was found in all test cases. Behavior consistent with preferential oxidation based on grain orientation was found in the iodine test cases.","PeriodicalId":509398,"journal":{"name":"Journal of Vacuum Science & Technology A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139962954","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}
Changda Zhu, Xi Qiu, Yuanming Li, Wei Zhang, Jian Yang, Yilong Zhong, Jiuguo Deng, Mingyang Zhou, Ning Liu, Jijun Yang
The effect of FeCrAl sublayer composition on the microstructure and lead-bismuth eutectic corrosion behavior of the FeCrAl/YSZ (Yttria-stabilized zirconia) composite coatings was systematically investigated by SEM and XRD. The results show that the FeCrAl sublayer as a diffusion barrier and a bonding layer is beneficial to improve the corrosion resistance of the coatings. After corrosion, a slow-growing, continuous, and protective Al-rich oxide is formed at the interface between the YSZ and FeCrAl sublayer, which effectively hinders the inward diffusion of oxygen atoms and the outward diffusion of iron atoms. Especially, the Fe-12Cr-7Al/YSZ coating exhibits the best corrosion resistance even after corrosion at 700 °C. The microscopic corrosion mechanism of FeCrAl/YSZ coatings is elucidated.
{"title":"Effect of FeCrAl sublayer composition on the microstructure and corrosion resistance of FeCrAl/yttria-stabilized zirconia composite coatings","authors":"Changda Zhu, Xi Qiu, Yuanming Li, Wei Zhang, Jian Yang, Yilong Zhong, Jiuguo Deng, Mingyang Zhou, Ning Liu, Jijun Yang","doi":"10.1116/6.0003114","DOIUrl":"https://doi.org/10.1116/6.0003114","url":null,"abstract":"The effect of FeCrAl sublayer composition on the microstructure and lead-bismuth eutectic corrosion behavior of the FeCrAl/YSZ (Yttria-stabilized zirconia) composite coatings was systematically investigated by SEM and XRD. The results show that the FeCrAl sublayer as a diffusion barrier and a bonding layer is beneficial to improve the corrosion resistance of the coatings. After corrosion, a slow-growing, continuous, and protective Al-rich oxide is formed at the interface between the YSZ and FeCrAl sublayer, which effectively hinders the inward diffusion of oxygen atoms and the outward diffusion of iron atoms. Especially, the Fe-12Cr-7Al/YSZ coating exhibits the best corrosion resistance even after corrosion at 700 °C. The microscopic corrosion mechanism of FeCrAl/YSZ coatings is elucidated.","PeriodicalId":509398,"journal":{"name":"Journal of Vacuum Science & Technology A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139686444","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}
Allan Lebreton, M. Besland, P.-Y. Jouan, Tatiana Signe, Cédric Mannequin, Mireille Richard-Plouet, Maryline Le Granvalet, Christophe Lethien, Thierry Brousse, Jérémy Barbé
Vanadium nitride (VN) thin films were prepared by reactive DC magnetron sputtering of a vanadium target using nitrogen as reactive gas. The structural, morphological, and compositional evolution of these films is described based on hysteresis diagrams plotting the sputtering power versus nitrogen flow rate. These diagrams, measured across various cathode voltages and discharge pressures, unveil three distinct deposition regimes: metallic, intermediate, and contaminated. The microstructure of the films was found to be closely linked to the deposition regime, ranging from dense and amorphous in the metallic regime to porous and crystalline in the contaminated regime, while the composition varies from vanadium-rich to near-stoichiometric VN. Sputtered VN thin films used as electrodes for microsupercapacitors were investigated by cyclic voltammetry. Results highlight that the intermediate deposition regime, characterized by high crystallinity and porosity, yields the highest capacitance values, above 900 F cm−3. Such high volumetric capacitance is attributed to the highly porous structure and large specific surface area. In addition, in these deposition conditions, films are composed of crystalline VN with a significant amount of amorphous VOx on the surface, which allow these thin film electrodes to behave both as current collectors and pseudocapacitive electrodes. This work gives detailed insights into VN thin film microstructure and composition in reactive sputtering based on hysteresis curves. It emphasizes how we could use these curves to target specific microstructure, composition, and eventually achieve functional properties. In particular, these findings have important implications for the design and optimization of microstructured electrodes for energy storage applications.
{"title":"Control of microstructure and composition of reactively sputtered vanadium nitride thin films based on hysteresis curves and application to microsupercapacitors","authors":"Allan Lebreton, M. Besland, P.-Y. Jouan, Tatiana Signe, Cédric Mannequin, Mireille Richard-Plouet, Maryline Le Granvalet, Christophe Lethien, Thierry Brousse, Jérémy Barbé","doi":"10.1116/5.0177028","DOIUrl":"https://doi.org/10.1116/5.0177028","url":null,"abstract":"Vanadium nitride (VN) thin films were prepared by reactive DC magnetron sputtering of a vanadium target using nitrogen as reactive gas. The structural, morphological, and compositional evolution of these films is described based on hysteresis diagrams plotting the sputtering power versus nitrogen flow rate. These diagrams, measured across various cathode voltages and discharge pressures, unveil three distinct deposition regimes: metallic, intermediate, and contaminated. The microstructure of the films was found to be closely linked to the deposition regime, ranging from dense and amorphous in the metallic regime to porous and crystalline in the contaminated regime, while the composition varies from vanadium-rich to near-stoichiometric VN. Sputtered VN thin films used as electrodes for microsupercapacitors were investigated by cyclic voltammetry. Results highlight that the intermediate deposition regime, characterized by high crystallinity and porosity, yields the highest capacitance values, above 900 F cm−3. Such high volumetric capacitance is attributed to the highly porous structure and large specific surface area. In addition, in these deposition conditions, films are composed of crystalline VN with a significant amount of amorphous VOx on the surface, which allow these thin film electrodes to behave both as current collectors and pseudocapacitive electrodes. This work gives detailed insights into VN thin film microstructure and composition in reactive sputtering based on hysteresis curves. It emphasizes how we could use these curves to target specific microstructure, composition, and eventually achieve functional properties. In particular, these findings have important implications for the design and optimization of microstructured electrodes for energy storage applications.","PeriodicalId":509398,"journal":{"name":"Journal of Vacuum Science & Technology A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139527157","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}
Ellipsometry is a material analytical method in which the desired parameters, for example, film thickness and index of refraction, are related to the instrument measurements through Maxwell’s equations, light wavelength, and measurement geometry. Consequently, obtaining the desired parameters has required solving the model equations using a wide variety of methods. A commonly used method is least squares curve fitting, frequently the Levenberg–Marquardt method. This numerical method depends upon not only the model but also the initial estimates of solution, the possible interference of local minima, and the algorithm stopping conditions. Being iterative, it also takes nonzero time. The work here demonstrates the use of artificial intelligence in the form of a multilayer perceptron artificial neural network to avoid these problems and find solutions in the millisecond time scale. This noniterative, stable, and fast performance lends itself to real-time, in situ monitoring of thin film growth. Examples for thin (up to 30 nm) films will be given using a multilayer perceptron configuration consisting of four input and four output neurons with two hidden layers of 40 neurons each. Solutions are predicted by the artificial neural network at each wavelength independently and do not rely on fitting functions which express a relationship between optical properties and wavelength.
{"title":"Numerical ellipsometry: Artificial intelligence for real-time, in situ absorbing film process control","authors":"F. Urban, D. Barton","doi":"10.1116/6.0003196","DOIUrl":"https://doi.org/10.1116/6.0003196","url":null,"abstract":"Ellipsometry is a material analytical method in which the desired parameters, for example, film thickness and index of refraction, are related to the instrument measurements through Maxwell’s equations, light wavelength, and measurement geometry. Consequently, obtaining the desired parameters has required solving the model equations using a wide variety of methods. A commonly used method is least squares curve fitting, frequently the Levenberg–Marquardt method. This numerical method depends upon not only the model but also the initial estimates of solution, the possible interference of local minima, and the algorithm stopping conditions. Being iterative, it also takes nonzero time. The work here demonstrates the use of artificial intelligence in the form of a multilayer perceptron artificial neural network to avoid these problems and find solutions in the millisecond time scale. This noniterative, stable, and fast performance lends itself to real-time, in situ monitoring of thin film growth. Examples for thin (up to 30 nm) films will be given using a multilayer perceptron configuration consisting of four input and four output neurons with two hidden layers of 40 neurons each. Solutions are predicted by the artificial neural network at each wavelength independently and do not rely on fitting functions which express a relationship between optical properties and wavelength.","PeriodicalId":509398,"journal":{"name":"Journal of Vacuum Science & Technology A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139528691","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}
Professor Joseph “Joe” Greene taught me a great deal about research, leadership, and how to succeed. He was a mentor and a tireless advocate for me over the course of my career. This article summarizes some of the work that my research group carried out, inspired by Prof. Greene but not in direct collaboration with him. Three examples of these efforts are provided, epitaxial growth of Cu(In,Ga)Se2 (CIGS) on GaAs by sputter deposition, synthesis of Cu-Mo metastable alloys by sputter deposition, and recrystallization of CIGS deposited at high rates by treatment with metal halides. These works were carried out with many collaborators who are acknowledged in the description of the research carried out by them and in the references where full details can be found.
{"title":"Processing and characterization of chalcopyrite semiconductors for photovoltaic applications","authors":"Angus Rockett","doi":"10.1116/6.0003227","DOIUrl":"https://doi.org/10.1116/6.0003227","url":null,"abstract":"Professor Joseph “Joe” Greene taught me a great deal about research, leadership, and how to succeed. He was a mentor and a tireless advocate for me over the course of my career. This article summarizes some of the work that my research group carried out, inspired by Prof. Greene but not in direct collaboration with him. Three examples of these efforts are provided, epitaxial growth of Cu(In,Ga)Se2 (CIGS) on GaAs by sputter deposition, synthesis of Cu-Mo metastable alloys by sputter deposition, and recrystallization of CIGS deposited at high rates by treatment with metal halides. These works were carried out with many collaborators who are acknowledged in the description of the research carried out by them and in the references where full details can be found.","PeriodicalId":509398,"journal":{"name":"Journal of Vacuum Science & Technology A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139528752","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}
M. Meindlhumer, T. Ziegelwanger, J. Grau, H. Sternschulte, M. Sztucki, D. Steinmüller-Nethl, J. Keckes
Chemical vapor deposition produced diamonds attract considerable scientific and industrial interest due to their exceptional mechanical and functional properties. Here, hot filament (HF) chemical vapor deposition was used to synthesize two diamond thin films with different cross-sectional microstructure and residual stresses. Structural characterization by scanning electron microscopy, Raman spectroscopy, and cross-sectional synchrotron x-ray nanodiffraction revealed different diamond morphologies. While the microcrystalline diamond film exhibits pronounced microstructural gradients expressed by gradually increasing (i) intensities of the 111 Debye-Scherrer rings, (ii) ⟨110⟩ fiber texture sharpness, (iii) grain size, and (iv) slightly oscillating residual stress at the level of −0.5 GPa, the nanocrystalline diamond film showed no pronounced cross-sectional variation of microstructure above the nucleation zone of ∼0.5 μm and a steady stress level of 0.25 GPa. In situ micromechanical cantilever bending tests revealed highly different mechanical properties of the two films. In detail, Young's modulus of 830 ± 53 and 459 ± 53 GPa, fracture stress of 12.4 ± 0.8 and 7.8 ± 1.0 GPa, and fracture toughness values of 6.9 ± 0.4 and 3.6 ± 0.3 MPa⋅m½ were evaluated for the micro- and nanocrystalline diamond films, respectively. In summary, this study provides valuable insights into the microstructure-residual stress correlation in micro- and nanocrystalline diamond films, especially illuminating their influence on micromechanical properties.
{"title":"Micromechanical properties of micro- and nanocrystalline CVD diamond thin films with gradient microstructures and stresses","authors":"M. Meindlhumer, T. Ziegelwanger, J. Grau, H. Sternschulte, M. Sztucki, D. Steinmüller-Nethl, J. Keckes","doi":"10.1116/6.0003235","DOIUrl":"https://doi.org/10.1116/6.0003235","url":null,"abstract":"Chemical vapor deposition produced diamonds attract considerable scientific and industrial interest due to their exceptional mechanical and functional properties. Here, hot filament (HF) chemical vapor deposition was used to synthesize two diamond thin films with different cross-sectional microstructure and residual stresses. Structural characterization by scanning electron microscopy, Raman spectroscopy, and cross-sectional synchrotron x-ray nanodiffraction revealed different diamond morphologies. While the microcrystalline diamond film exhibits pronounced microstructural gradients expressed by gradually increasing (i) intensities of the 111 Debye-Scherrer rings, (ii) ⟨110⟩ fiber texture sharpness, (iii) grain size, and (iv) slightly oscillating residual stress at the level of −0.5 GPa, the nanocrystalline diamond film showed no pronounced cross-sectional variation of microstructure above the nucleation zone of ∼0.5 μm and a steady stress level of 0.25 GPa. In situ micromechanical cantilever bending tests revealed highly different mechanical properties of the two films. In detail, Young's modulus of 830 ± 53 and 459 ± 53 GPa, fracture stress of 12.4 ± 0.8 and 7.8 ± 1.0 GPa, and fracture toughness values of 6.9 ± 0.4 and 3.6 ± 0.3 MPa⋅m½ were evaluated for the micro- and nanocrystalline diamond films, respectively. In summary, this study provides valuable insights into the microstructure-residual stress correlation in micro- and nanocrystalline diamond films, especially illuminating their influence on micromechanical properties.","PeriodicalId":509398,"journal":{"name":"Journal of Vacuum Science & Technology A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139532167","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}
Xiaoning Zhang, Haoyu Dong, Chao Yang, Xi Liang, Xing Li, Jia-yue Yang, Linhua Liu
β-Ga2O3 is a new generation of semiconductor material with a wide bandgap of 4.9 eV. However, the β-Ga2O3 devices inevitably produce defects within them after irradiation, leading to changes in their thermal conductivities. At present, the effect of radiation-damage-induced defects on thermal conductivity of β-Ga2O3 has not been carried out. Herein, we have employed molecular dynamics simulations to investigate the impact of defects on the thermal transport of β-Ga2O3, and the obtained thermal conductivity of non-defect β-Ga2O3 is in good agreement with recent reports. Our findings indicate that the thermal conductivity of β-Ga2O3 at room temperature exhibits a consistent decrease with an increase in the concentration of Ga vacancies, but shows a decreasing and then increasing trend as the number of O vacancies increases. In addition, doping/alloying is found to improve the irradiation resistance of β-Ga2O3 based on reported defect formation energy calculations, so the mechanism of alloying effect on the thermal conductivity is deeply analyzed through first-principles calculations. Moreover, the lattice thermal conductivities of ordered InGaO3 and BGaO3 alloys are predicted by solving the phonon Boltzmann transport equation. The obtained results that κ(Ga2O3) = κ(BGaO3) > κ(InGaO3) are attributed to the combined effect of volume, specific heat capacity, group velocity, and phonon lifetime of the three materials. This work can help to disclose the radiation damage influence on thermal properties of β-Ga2O3 semiconductors.
β-Ga2O3 是新一代半导体材料，具有 4.9 eV 的宽带隙。然而，β-Ga2O3 器件在辐照后不可避免地会在内部产生缺陷，从而导致其热导率发生变化。目前，还没有人研究过辐射损伤引起的缺陷对 β-Ga2O3 热导率的影响。在此，我们采用分子动力学模拟研究了缺陷对β-Ga2O3热传输的影响，得到的无缺陷β-Ga2O3的热导率与最近的报道十分吻合。我们的研究结果表明，β-Ga2O3 在室温下的热导率随 Ga 空位浓度的增加而持续下降，但随着 O 空位数量的增加，热导率呈现先降后升的趋势。此外，根据所报道的缺陷形成能计算发现，掺杂/合金化能改善β-Ga2O3的抗辐照性能，因此通过第一性原理计算深入分析了合金化对热导率的影响机制。此外，通过求解声子波尔兹曼输运方程，预测了有序 InGaO3 和 BGaO3 合金的晶格热导率。得出的κ(Ga2O3) = κ(BGaO3) > κ(InGaO3) 的结果归因于三种材料的体积、比热容、群速度和声子寿命的综合影响。这项工作有助于揭示辐射损伤对β-Ga2O3半导体热特性的影响。
{"title":"Thermal transport of defective β-Ga2O3 and B(In)GaO3 alloys from atomistic simulations","authors":"Xiaoning Zhang, Haoyu Dong, Chao Yang, Xi Liang, Xing Li, Jia-yue Yang, Linhua Liu","doi":"10.1116/6.0003214","DOIUrl":"https://doi.org/10.1116/6.0003214","url":null,"abstract":"β-Ga2O3 is a new generation of semiconductor material with a wide bandgap of 4.9 eV. However, the β-Ga2O3 devices inevitably produce defects within them after irradiation, leading to changes in their thermal conductivities. At present, the effect of radiation-damage-induced defects on thermal conductivity of β-Ga2O3 has not been carried out. Herein, we have employed molecular dynamics simulations to investigate the impact of defects on the thermal transport of β-Ga2O3, and the obtained thermal conductivity of non-defect β-Ga2O3 is in good agreement with recent reports. Our findings indicate that the thermal conductivity of β-Ga2O3 at room temperature exhibits a consistent decrease with an increase in the concentration of Ga vacancies, but shows a decreasing and then increasing trend as the number of O vacancies increases. In addition, doping/alloying is found to improve the irradiation resistance of β-Ga2O3 based on reported defect formation energy calculations, so the mechanism of alloying effect on the thermal conductivity is deeply analyzed through first-principles calculations. Moreover, the lattice thermal conductivities of ordered InGaO3 and BGaO3 alloys are predicted by solving the phonon Boltzmann transport equation. The obtained results that κ(Ga2O3) = κ(BGaO3) > κ(InGaO3) are attributed to the combined effect of volume, specific heat capacity, group velocity, and phonon lifetime of the three materials. This work can help to disclose the radiation damage influence on thermal properties of β-Ga2O3 semiconductors.","PeriodicalId":509398,"journal":{"name":"Journal of Vacuum Science & Technology A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139531825","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}
Takahiro Ozawa, Kaidong Wang, K. Nishio, R. Shimizu, T. Hitosugi, K. Fukutani
We synthesized an epitaxial film of high-entropy perovskite oxide (HEPO) consisting of three elements (Ca, Sr, Ba) in the A site and 12 elements (Si, Ti, Cr, Mn, Fe, Co, Ni, Ge, Zr, Sn, Ce, Hf) in the B site of ABO3, and investigated hydrogen absorption properties in the HEPO film. The hydrogen depth profile was measured by nuclear reaction analysis via the 1H(15N,αγ)12C reaction, showing the hydrogen absorption in the HEPO film with a maximum atomic concentration of 0.3 in the ABO3 unit. The diffusion coefficient of H in the film was analyzed from the H depth profile, and the activation barrier for diffusion was estimated to be (0.54±0.13) eV. An absorption band was observed at 3290 cm−1 in the infrared absorption spectrum, which corresponds to the O–H stretching vibration. Simultaneous measurements of nuclear reaction and resistance revealed that the HEPO film remained electrically insulating regardless of the hydrogen concentration. We demonstrated that hydrogen is incorporated in HEPO forming OH species while keeping HEPO electrically insulating.
{"title":"Hydrogen absorption in an epitaxial thin film of high-entropy perovskite oxide","authors":"Takahiro Ozawa, Kaidong Wang, K. Nishio, R. Shimizu, T. Hitosugi, K. Fukutani","doi":"10.1116/6.0003256","DOIUrl":"https://doi.org/10.1116/6.0003256","url":null,"abstract":"We synthesized an epitaxial film of high-entropy perovskite oxide (HEPO) consisting of three elements (Ca, Sr, Ba) in the A site and 12 elements (Si, Ti, Cr, Mn, Fe, Co, Ni, Ge, Zr, Sn, Ce, Hf) in the B site of ABO3, and investigated hydrogen absorption properties in the HEPO film. The hydrogen depth profile was measured by nuclear reaction analysis via the 1H(15N,αγ)12C reaction, showing the hydrogen absorption in the HEPO film with a maximum atomic concentration of 0.3 in the ABO3 unit. The diffusion coefficient of H in the film was analyzed from the H depth profile, and the activation barrier for diffusion was estimated to be (0.54±0.13) eV. An absorption band was observed at 3290 cm−1 in the infrared absorption spectrum, which corresponds to the O–H stretching vibration. Simultaneous measurements of nuclear reaction and resistance revealed that the HEPO film remained electrically insulating regardless of the hydrogen concentration. We demonstrated that hydrogen is incorporated in HEPO forming OH species while keeping HEPO electrically insulating.","PeriodicalId":509398,"journal":{"name":"Journal of Vacuum Science & Technology A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139531883","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}
Self-powered photodetectors, requiring no external bias, offer distinct advantages that render them ideal for a broad spectrum of applications. Efficient carrier separation and collection stand as foundational elements in the operation of these photodetectors. In this study, we delve into the refinement of Cu2O/ZnO heterojunction photodetectors. By varying the thickness of the ZnO layer, we controlled the separation and capture of carriers at the heterojunction, thus achieving adjustable photodetector performance. Our experimental findings reveal pronounced performance trends related to different wavelength bands, with particular significance in the ultraviolet and visible exploration. We observe a distinctive pattern marked by an initial performance increase followed by a subsequent decline. This intriguing phenomenon implies that meticulous control over carrier separation and collection within the heterojunction can be realized by fine-tuning the transmission distance, ultimately allowing us to adjust the photodetector’s responsivity.
{"title":"Cu2O/ZnO heterojunction self-powered photodetector performance regulation","authors":"Siyuan Li, Man Zhao, Dayong Jiang, Mingyang Li, Meijiao Wang, Yanyan Peng, Jingda Gu","doi":"10.1116/6.0003274","DOIUrl":"https://doi.org/10.1116/6.0003274","url":null,"abstract":"Self-powered photodetectors, requiring no external bias, offer distinct advantages that render them ideal for a broad spectrum of applications. Efficient carrier separation and collection stand as foundational elements in the operation of these photodetectors. In this study, we delve into the refinement of Cu2O/ZnO heterojunction photodetectors. By varying the thickness of the ZnO layer, we controlled the separation and capture of carriers at the heterojunction, thus achieving adjustable photodetector performance. Our experimental findings reveal pronounced performance trends related to different wavelength bands, with particular significance in the ultraviolet and visible exploration. We observe a distinctive pattern marked by an initial performance increase followed by a subsequent decline. This intriguing phenomenon implies that meticulous control over carrier separation and collection within the heterojunction can be realized by fine-tuning the transmission distance, ultimately allowing us to adjust the photodetector’s responsivity.","PeriodicalId":509398,"journal":{"name":"Journal of Vacuum Science & Technology A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139392043","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}
X-ray photoelectron spectroscopy is a major and valuable chemical analysis technique that can bring a wide range of information if one takes time to carefully interpret the spectra. In particular, many metrological developments deal with the modeling of photoelectron peaks while X-Auger transitions still remain hardly exploited. Here, an innovative approach examining these spectral features in a complementary way is presented and illustrated on a concrete case dealing with chemical changes of indium in the InSb semiconductor during its air aging. Indium contains an extensive range of photopeaks along the energy scale, meaning electrons emitted from different escape depths are present on the same widescan spectrum, and, thus, information from different depths is accessible. Specifically, this study focuses on indium’s X-Auger electron spectroscopy (X-AES) transitions and decomposition to track the outer surface chemistry evolution of the InSb semiconductor. To this end, we compared linear and nonlinear least-squares approaches to decompose In M4,5N4,5N4,5 X-AES transition and demonstrate oxide growth progression. For both approaches, we applied the vectorial method (also known as the informed amorphous sample model) to retrieve the different chemical environments present during air aging. Linear and nonlinear least-squares approaches were both found to yield comparable results, with a comparative error of less than 10%. Over time, a progressive growth of the oxide layer was demonstrated, ranging from 0.3 ± 0.2 to 2.9 ± 0.2 nm using the X-AES transitions. Additionally, decomposition of the In 3d and In 4d photoelectron peaks showed a lower thickness of oxide with time due to the lesser surface sensitivity of these peaks.
X 射线光电子能谱是一种重要而有价值的化学分析技术，只要花时间仔细解读光谱，就能获得广泛的信息。特别是，许多计量学的发展都涉及到光电子峰的建模，而 X-Auger 转换仍然很少被利用。本文介绍了一种以互补方式检查这些光谱特征的创新方法，并以 InSb 半导体在空气老化过程中铟的化学变化为具体案例进行了说明。铟在能级上包含大量光峰，这意味着在同一宽扫描光谱上存在不同逸出深度发射的电子，因此可以获取不同深度的信息。具体来说，本研究重点关注铟的 X-Auger 电子能谱（X-AES）跃迁和分解，以跟踪 InSb 半导体的外表面化学演变。为此，我们比较了线性和非线性最小二乘法来分解 In M4,5N4,5N4,5 X-AES 转变，并展示氧化物的生长过程。对于这两种方法，我们都采用了矢量法（也称为知情无定形样品模型）来检索空气老化过程中存在的不同化学环境。结果发现，线性和非线性最小二乘法得出的结果相当，误差均小于 10%。随着时间的推移，氧化层逐渐增长，X-AES 晶体转变的范围从 0.3 ± 0.2 纳米到 2.9 ± 0.2 纳米不等。此外，In 3d 和 In 4d 光电子峰的分解显示，随着时间的推移，氧化层的厚度会降低，这是因为这些峰的表面灵敏度较低。
{"title":"Determination of the X-Auger electron spectroscopy evolution of indium in InSb by linear and nonlinear least squares approaches","authors":"S. Béchu, Neal Fairley","doi":"10.1116/6.0003086","DOIUrl":"https://doi.org/10.1116/6.0003086","url":null,"abstract":"X-ray photoelectron spectroscopy is a major and valuable chemical analysis technique that can bring a wide range of information if one takes time to carefully interpret the spectra. In particular, many metrological developments deal with the modeling of photoelectron peaks while X-Auger transitions still remain hardly exploited. Here, an innovative approach examining these spectral features in a complementary way is presented and illustrated on a concrete case dealing with chemical changes of indium in the InSb semiconductor during its air aging. Indium contains an extensive range of photopeaks along the energy scale, meaning electrons emitted from different escape depths are present on the same widescan spectrum, and, thus, information from different depths is accessible. Specifically, this study focuses on indium’s X-Auger electron spectroscopy (X-AES) transitions and decomposition to track the outer surface chemistry evolution of the InSb semiconductor. To this end, we compared linear and nonlinear least-squares approaches to decompose In M4,5N4,5N4,5 X-AES transition and demonstrate oxide growth progression. For both approaches, we applied the vectorial method (also known as the informed amorphous sample model) to retrieve the different chemical environments present during air aging. Linear and nonlinear least-squares approaches were both found to yield comparable results, with a comparative error of less than 10%. Over time, a progressive growth of the oxide layer was demonstrated, ranging from 0.3 ± 0.2 to 2.9 ± 0.2 nm using the X-AES transitions. Additionally, decomposition of the In 3d and In 4d photoelectron peaks showed a lower thickness of oxide with time due to the lesser surface sensitivity of these peaks.","PeriodicalId":509398,"journal":{"name":"Journal of Vacuum Science & Technology A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139454300","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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