In this study, carbon/TiO2 composite particles were prepared by pyrolyzing metal-organic framework (MOF) particles. The structure and conductivity of composite particles was characterized and the electrorheological (ER) effect of composite particles dispersed in silicone oil was measured under electric fields. It is interesting that the composite particle suspensions exhibit a tunable electro-response from negative to positive ER effect depending on pyrolysis temperatures. The suspension containing particles produced at 400 °C shows abnormal negative ER effect, which can be explained by the conduction model because 400 °C-pyrolysis destroys the bonds between organic linkers and Ti—O clusters to yield composite with lower conductivity than silicone oil. However, the suspension containing particles produced at 440 °C still shows negative ER effect, which cannot be explained by the conduction model because the conductivity of composite exceeds that of silicone oil. Through microscopic observation and dielectric spectra analysis, we clarified that the absence of available interfacial polarization in the suspensions of particles produced at lower pyrolysis temperature than 440 °C is the real reason of negative ER effect. Increasing pyrolysis temperatures to 480 and 520 °C improves the carbonization level and conductivity of composites, leading to large interfacial polarization and positive ER effect of corresponding suspensions. The suspension containing particles produced at 520 °C exhibits the optimal positive ER effect. This work demonstrates the crucial role of interfacial polarization in determining positive or negative ER effect through using MOF-derived carbonaceous composites with tunable structure and electric properties.
{"title":"Tuning pyrolyzing temperature to switch electrorheological effect from negative to positive in MIL-125(Ti)-derived carbon/TiO2 composite particles: Crucial role of interfacial polarization","authors":"Wuyang Nie, Ruijing Ma, Libing Duan, Xiaoru Zhao, Liqin Xiang, Haoming Pang, Jianbo Yin","doi":"10.1063/5.0297458","DOIUrl":"https://doi.org/10.1063/5.0297458","url":null,"abstract":"In this study, carbon/TiO2 composite particles were prepared by pyrolyzing metal-organic framework (MOF) particles. The structure and conductivity of composite particles was characterized and the electrorheological (ER) effect of composite particles dispersed in silicone oil was measured under electric fields. It is interesting that the composite particle suspensions exhibit a tunable electro-response from negative to positive ER effect depending on pyrolysis temperatures. The suspension containing particles produced at 400 °C shows abnormal negative ER effect, which can be explained by the conduction model because 400 °C-pyrolysis destroys the bonds between organic linkers and Ti—O clusters to yield composite with lower conductivity than silicone oil. However, the suspension containing particles produced at 440 °C still shows negative ER effect, which cannot be explained by the conduction model because the conductivity of composite exceeds that of silicone oil. Through microscopic observation and dielectric spectra analysis, we clarified that the absence of available interfacial polarization in the suspensions of particles produced at lower pyrolysis temperature than 440 °C is the real reason of negative ER effect. Increasing pyrolysis temperatures to 480 and 520 °C improves the carbonization level and conductivity of composites, leading to large interfacial polarization and positive ER effect of corresponding suspensions. The suspension containing particles produced at 520 °C exhibits the optimal positive ER effect. This work demonstrates the crucial role of interfacial polarization in determining positive or negative ER effect through using MOF-derived carbonaceous composites with tunable structure and electric properties.","PeriodicalId":14741,"journal":{"name":"Japanese Journal of Applied Physics","volume":"138 21","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147331040","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-25DOI: 10.35848/1347-4065/ae2407
Hao Yang, Lin Zha, Feng Shao, Shaoqing Xiao, Xi Wan, Xiaofeng Gu
Abstract Electrolyte-gated transistors (EGTs) represent a highly intriguing device platform for intelligent bio- and chemical sensing. To enable effective humidity sensing with cellulose nanofibers-gated in-plane-gate indium gallium zinc oxide transistors. This work adopted three synergistic methods to tune the gate controllability: ion doping of the solid electrolyte, gate electrode restructuring, and application of pulsed gate voltages. Cellulose nanofibers gate electrolyte was doped with LiClO 4 to increase ionic conductivity and electric double layer capacitance. A C-shaped in-plane-gate design expanded the electrolyte region between the gate and channel, enabling a wider electric field distribution for improved gate control. With pulsed gate voltage operation, duty ratio adjustment revealed a sharply enhanced humidity response compared to quasi-static operation, achieving a higher current response ratio of 69.2 between 80% and 20% relative humidity. These results demonstrate that by combining material, structural, and signal engineering, the potential of in-plane-gate EGTs for humidity sensing is unlocked for humidity sensing applications.
{"title":"Gate tuning of cellulose nanofibers-gated in-plane-gate IGZO transistors for humidity sensing","authors":"Hao Yang, Lin Zha, Feng Shao, Shaoqing Xiao, Xi Wan, Xiaofeng Gu","doi":"10.35848/1347-4065/ae2407","DOIUrl":"https://doi.org/10.35848/1347-4065/ae2407","url":null,"abstract":"Abstract Electrolyte-gated transistors (EGTs) represent a highly intriguing device platform for intelligent bio- and chemical sensing. To enable effective humidity sensing with cellulose nanofibers-gated in-plane-gate indium gallium zinc oxide transistors. This work adopted three synergistic methods to tune the gate controllability: ion doping of the solid electrolyte, gate electrode restructuring, and application of pulsed gate voltages. Cellulose nanofibers gate electrolyte was doped with LiClO 4 to increase ionic conductivity and electric double layer capacitance. A C-shaped in-plane-gate design expanded the electrolyte region between the gate and channel, enabling a wider electric field distribution for improved gate control. With pulsed gate voltage operation, duty ratio adjustment revealed a sharply enhanced humidity response compared to quasi-static operation, achieving a higher current response ratio of 69.2 between 80% and 20% relative humidity. These results demonstrate that by combining material, structural, and signal engineering, the potential of in-plane-gate EGTs for humidity sensing is unlocked for humidity sensing applications.","PeriodicalId":14741,"journal":{"name":"Japanese Journal of Applied Physics","volume":"64 12","pages":"126505-126505"},"PeriodicalIF":0.0,"publicationDate":"2025-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147382086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xinmiao Gai, Cun You, Yu-Qi Gao, Z.W. Li, Hetian Liu, Wei Zhao, Pinwen Zhu, Xin Wang
Bi2Ru2O7 is a weak metal pyrochlore with good conductivity. Due to the static disordered displacement caused by the Bi 6s lone pair, which distorts the [RuO6] octahedron, the t2g orbitals split into e'g and a1g states. This results in the opening of a bandgap at the Fermi level, leading to reduced electrical conductivity in the sample compared to its standard structure. The electrical resistivity, temperature difference, and Seebeck coefficient of the sample were synchronously observed using high-temperature and high-pressure in situ testing assembly. The Seebeck coefficient and temperature discontinuity of the sample occurred at 4.0 GPa at 878.9 K, and the final value of resistivity showed a significant decrease after returning to ambient temperature at 4.0 GPa, but remained within the range of 10−4 Ω m. The x-ray diffraction (XRD) analysis after high-temperature and high-pressure treatment confirmed that the sample underwent irreversible expansion at 4.0 GPa at 878.9 K. In situ high-temperature XRD indicates that irreversible expansion of the sample cannot be achieved by high-temperature treatment at ambient pressure. High-temperature and high-pressure treatment effectively expands the atomic spacing, which can alleviate the displacement of shared oxygen in [RuO6] octahedra caused by the Bi 6s lone pair, reduce octahedral distortion, and thus improve the semi-metallic bandgap caused by static disordered displacement, which provides a new idea for improving the performance of bismuth ruthenate and its composite electrode materials. In addition, expansion is beneficial for the replacement process of the sample as a matrix material, indicating its potential application value in the field of nuclear waste solidification and as a doped matrix material.
{"title":"Irreversible expansion and distortion relief of bismuth ruthenate under high temperature and high pressure","authors":"Xinmiao Gai, Cun You, Yu-Qi Gao, Z.W. Li, Hetian Liu, Wei Zhao, Pinwen Zhu, Xin Wang","doi":"10.1063/5.0288809","DOIUrl":"https://doi.org/10.1063/5.0288809","url":null,"abstract":"Bi2Ru2O7 is a weak metal pyrochlore with good conductivity. Due to the static disordered displacement caused by the Bi 6s lone pair, which distorts the [RuO6] octahedron, the t2g orbitals split into e'g and a1g states. This results in the opening of a bandgap at the Fermi level, leading to reduced electrical conductivity in the sample compared to its standard structure. The electrical resistivity, temperature difference, and Seebeck coefficient of the sample were synchronously observed using high-temperature and high-pressure in situ testing assembly. The Seebeck coefficient and temperature discontinuity of the sample occurred at 4.0 GPa at 878.9 K, and the final value of resistivity showed a significant decrease after returning to ambient temperature at 4.0 GPa, but remained within the range of 10−4 Ω m. The x-ray diffraction (XRD) analysis after high-temperature and high-pressure treatment confirmed that the sample underwent irreversible expansion at 4.0 GPa at 878.9 K. In situ high-temperature XRD indicates that irreversible expansion of the sample cannot be achieved by high-temperature treatment at ambient pressure. High-temperature and high-pressure treatment effectively expands the atomic spacing, which can alleviate the displacement of shared oxygen in [RuO6] octahedra caused by the Bi 6s lone pair, reduce octahedral distortion, and thus improve the semi-metallic bandgap caused by static disordered displacement, which provides a new idea for improving the performance of bismuth ruthenate and its composite electrode materials. In addition, expansion is beneficial for the replacement process of the sample as a matrix material, indicating its potential application value in the field of nuclear waste solidification and as a doped matrix material.","PeriodicalId":14741,"journal":{"name":"Japanese Journal of Applied Physics","volume":"138 13","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.aip.org/aip/jap/article-pdf/doi/10.1063/5.0288809/20723830/135901_1_5.0288809.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147333494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yang Feng, Peiyan Liu, Yi Qiao, Bin Zhou, Kai Shang, Mingru Li, Shengtao Li
The demand for epoxy resin (EP) with superior dielectric strength is critical in advanced power equipment. Here, we aimed to construct EP with enhanced dielectric strength via molecular design. Simulations indicated that substituting the CH3 groups in bisphenol A EP with CF3 significantly improved charge transfer, which mostly led to an enhanced trap level and dielectric strength. Guided by simulations, we developed a synthetic pathway to produce fluorinated EP (FEP), which was subsequently validated that the molecular structure of the synthesized polymer aligned with expectations. Compared to traditional bisphenol A EP, a deeper trap was induced by the CF3 group, and the dielectric strength improved from 366.39 to 483.62 kV/mm, representing an increase of over 30%. We elucidated that the substantial enhancement in the breakdown performance of FEP can be attributed to the trapping effect of these traps on charge migration. The increased trap levels effectively inhibit the migration of carriers, thereby reducing both conductivity and carrier mobility, resulting in a higher threshold for discharge initiation. Our research holds significant implications to construct EP polymers tailored for advanced power equipment through strategic molecular design.
{"title":"Constructing epoxy polymer with significantly increased dielectric strength through molecular design by introducing deep trap","authors":"Yang Feng, Peiyan Liu, Yi Qiao, Bin Zhou, Kai Shang, Mingru Li, Shengtao Li","doi":"10.1063/5.0283922","DOIUrl":"https://doi.org/10.1063/5.0283922","url":null,"abstract":"The demand for epoxy resin (EP) with superior dielectric strength is critical in advanced power equipment. Here, we aimed to construct EP with enhanced dielectric strength via molecular design. Simulations indicated that substituting the CH3 groups in bisphenol A EP with CF3 significantly improved charge transfer, which mostly led to an enhanced trap level and dielectric strength. Guided by simulations, we developed a synthetic pathway to produce fluorinated EP (FEP), which was subsequently validated that the molecular structure of the synthesized polymer aligned with expectations. Compared to traditional bisphenol A EP, a deeper trap was induced by the CF3 group, and the dielectric strength improved from 366.39 to 483.62 kV/mm, representing an increase of over 30%. We elucidated that the substantial enhancement in the breakdown performance of FEP can be attributed to the trapping effect of these traps on charge migration. The increased trap levels effectively inhibit the migration of carriers, thereby reducing both conductivity and carrier mobility, resulting in a higher threshold for discharge initiation. Our research holds significant implications to construct EP polymers tailored for advanced power equipment through strategic molecular design.","PeriodicalId":14741,"journal":{"name":"Japanese Journal of Applied Physics","volume":"138 9","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.aip.org/aip/jap/article-pdf/doi/10.1063/5.0283922/20678635/095103_1_5.0283922.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147332173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Photoconductive detectors based on zinc oxide (ZnO) thin films have garnered significant attention in optoelectronic applications owing to their simplified device architecture, well-established fabrication processes, and scalability for industrial production. The buffer layer, as a factor affecting device performance, also needs to be investigated. This study systematically investigates the critical role of the buffer layer in modulating the performance metrics of ZnO film photodetectors. Through the comparative analysis of devices fabricated on glass substrates with distinct buffer configurations (CuO monolayer vs SiO2/CuO bilayer), we reveal the substantial modulation of photoresponse characteristics. The ZnO/CuO heterostructure exhibits a suppressed dark current (reduced by 20%) and photocurrent (reduced by 67%) relative to the reference device (ZnO film photodetector or PD), accompanied by prolonged response times (τrise = 3.3 s, τdecay = 15.4 s). Introducing an SiO2 insulated layer (200 nm) can lead to charge redistribution in the CuO layer and ZnO layer, achieving an enhanced on/off ratio (Iphoto/Idark = 1.1 × 102) with accelerated decay kinetics (τdecay = 10.5 s). These performance modifications originate from the synergistic effects of type-II band alignment at the ZnO/CuO interface and interfacial capacitance modulation. This work establishes a quantitative framework for failure mode analysis in oxide-based optoelectronics, providing a critical insight for device optimization strategies.
{"title":"Influence of buffer layer on the performance of ZnO film based photoconductive detectors","authors":"Pyong Hwa Hong, Leyao Wu, Xinnan Shi, Peng Hu, Haibo Fan, Feng Teng","doi":"10.1063/5.0273458","DOIUrl":"https://doi.org/10.1063/5.0273458","url":null,"abstract":"Photoconductive detectors based on zinc oxide (ZnO) thin films have garnered significant attention in optoelectronic applications owing to their simplified device architecture, well-established fabrication processes, and scalability for industrial production. The buffer layer, as a factor affecting device performance, also needs to be investigated. This study systematically investigates the critical role of the buffer layer in modulating the performance metrics of ZnO film photodetectors. Through the comparative analysis of devices fabricated on glass substrates with distinct buffer configurations (CuO monolayer vs SiO2/CuO bilayer), we reveal the substantial modulation of photoresponse characteristics. The ZnO/CuO heterostructure exhibits a suppressed dark current (reduced by 20%) and photocurrent (reduced by 67%) relative to the reference device (ZnO film photodetector or PD), accompanied by prolonged response times (τrise = 3.3 s, τdecay = 15.4 s). Introducing an SiO2 insulated layer (200 nm) can lead to charge redistribution in the CuO layer and ZnO layer, achieving an enhanced on/off ratio (Iphoto/Idark = 1.1 × 102) with accelerated decay kinetics (τdecay = 10.5 s). These performance modifications originate from the synergistic effects of type-II band alignment at the ZnO/CuO interface and interfacial capacitance modulation. This work establishes a quantitative framework for failure mode analysis in oxide-based optoelectronics, providing a critical insight for device optimization strategies.","PeriodicalId":14741,"journal":{"name":"Japanese Journal of Applied Physics","volume":"138 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147333140","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Solvent-free polyelectrolyte elastomers, which are resistant to leakage, hold significant promise for large-scale engineering applications of stretchable ionotronic devices. However, the viscoelastic nature of ionized polymer networks introduces complexities in mechanical performance, highlighting the need for a deeper understanding of their visco-hyperelastic properties. In this study, a poly[1-[2-acryloyloxyethyl]-3-butylimidazolium bis(trifluoromethane) sulfonimide-co-methyl acrylate] elastomer is synthesized as the model material, with controlled covalent crosslinker densities and tailored ionic-to-neutral segment ratios to systematically modify its molecular structures. Through experimental mechanical characterizations—including tensile, hysteresis, and relaxation tests—the effects of network structure and strain rates on the material's responses are investigated. The results reveal a significant rate dependence and the Mullins effect. To model these behaviors, the Yeoh hyperelastic model, incorporating the Mullins effect, is employed to describe the nonlinear elastic response, while a nonlinear power law model is introduced to capture the time-dependent viscoelastic deformation. The proposed modeling framework demonstrates excellent agreements with the experimental data, effectively capturing the complex mechanical behaviors in various tests. This study provides valuable insights into the visco-hyperelastic behaviors of polyelectrolyte elastomers by mapping microscopic molecular structures to macroscopic mechanical performance.
{"title":"Experiments and numerical modeling of the visco-hyperelastic behaviors of polyelectrolyte elastomers","authors":"Mohammad Reza Adibeig, Canhui Yang","doi":"10.1063/5.0267552","DOIUrl":"https://doi.org/10.1063/5.0267552","url":null,"abstract":"Solvent-free polyelectrolyte elastomers, which are resistant to leakage, hold significant promise for large-scale engineering applications of stretchable ionotronic devices. However, the viscoelastic nature of ionized polymer networks introduces complexities in mechanical performance, highlighting the need for a deeper understanding of their visco-hyperelastic properties. In this study, a poly[1-[2-acryloyloxyethyl]-3-butylimidazolium bis(trifluoromethane) sulfonimide-co-methyl acrylate] elastomer is synthesized as the model material, with controlled covalent crosslinker densities and tailored ionic-to-neutral segment ratios to systematically modify its molecular structures. Through experimental mechanical characterizations—including tensile, hysteresis, and relaxation tests—the effects of network structure and strain rates on the material's responses are investigated. The results reveal a significant rate dependence and the Mullins effect. To model these behaviors, the Yeoh hyperelastic model, incorporating the Mullins effect, is employed to describe the nonlinear elastic response, while a nonlinear power law model is introduced to capture the time-dependent viscoelastic deformation. The proposed modeling framework demonstrates excellent agreements with the experimental data, effectively capturing the complex mechanical behaviors in various tests. This study provides valuable insights into the visco-hyperelastic behaviors of polyelectrolyte elastomers by mapping microscopic molecular structures to macroscopic mechanical performance.","PeriodicalId":14741,"journal":{"name":"Japanese Journal of Applied Physics","volume":"137 19","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147331077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xingliang Xu, Yun Wang, Liang Xu, Yuke Li, Xing’ao Li
Anhydrous phosphate compounds based on 3d transition metal ions can exhibit rich physical behaviors in fundamental condensed matter physics. Herein, we report the structures and low-dimensional quantum magnetism in potassium-based phosphates, KMPO4 (M = Cu, Co), by cooperation of experimental investigations and first-principles density functional theory (DFT) calculations. Magnetic susceptibility measurement performed on KCuPO4 reveals the presence of strong quasi-one-dimensional antiferromagnetic (AFM) behavior with S=12 Cu2+ Heisenberg spin chains. The analysis of heat capacity data verifies the distinct AFM order occurs at TN = 14.1 K obtained from the -susceptibility, while cobalt phosphate KCoPO4 shows no magnetic ordering down to T = 1.9 K. Furthermore, the fairly small ratio of J*/|J| ≈ 3.85 × 10−2, where J/kB (=−141.86 K) is the nearest-neighbor spin-exchange coupling parameter estimated from susceptibility data and J*/kB (≈5.46 K) is the interchain coupling under the mean field approximation, respectively, providing additional evidence that KCuPO4 is almost an ideal one-dimensional AFM compound. Our DFT calculations confirmed that KCuPO4 has a magnetic sublattice in which one-dimensional AFM exchange interactions are weakly coupled ferromagnetic chains. In addition, significant magnetic frustrations are verified in both KCuPO4 and KCoPO4, implying the possibility of a quantum magnetic phase in this phosphate family.
{"title":"Low-dimensional quantum antiferromagnetism in frustrated potassium 3<i>d</i> transition metal (II) phosphates: Insights from experimental and first-principles investigations","authors":"Xingliang Xu, Yun Wang, Liang Xu, Yuke Li, Xing’ao Li","doi":"10.1063/5.0262043","DOIUrl":"https://doi.org/10.1063/5.0262043","url":null,"abstract":"Anhydrous phosphate compounds based on 3d transition metal ions can exhibit rich physical behaviors in fundamental condensed matter physics. Herein, we report the structures and low-dimensional quantum magnetism in potassium-based phosphates, KMPO4 (M = Cu, Co), by cooperation of experimental investigations and first-principles density functional theory (DFT) calculations. Magnetic susceptibility measurement performed on KCuPO4 reveals the presence of strong quasi-one-dimensional antiferromagnetic (AFM) behavior with S=12 Cu2+ Heisenberg spin chains. The analysis of heat capacity data verifies the distinct AFM order occurs at TN = 14.1 K obtained from the -susceptibility, while cobalt phosphate KCoPO4 shows no magnetic ordering down to T = 1.9 K. Furthermore, the fairly small ratio of J*/|J| ≈ 3.85 × 10−2, where J/kB (=−141.86 K) is the nearest-neighbor spin-exchange coupling parameter estimated from susceptibility data and J*/kB (≈5.46 K) is the interchain coupling under the mean field approximation, respectively, providing additional evidence that KCuPO4 is almost an ideal one-dimensional AFM compound. Our DFT calculations confirmed that KCuPO4 has a magnetic sublattice in which one-dimensional AFM exchange interactions are weakly coupled ferromagnetic chains. In addition, significant magnetic frustrations are verified in both KCuPO4 and KCoPO4, implying the possibility of a quantum magnetic phase in this phosphate family.","PeriodicalId":14741,"journal":{"name":"Japanese Journal of Applied Physics","volume":"137 17","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147332323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhongyang Li, Yiming Wang, Xiaohui Zeng, Shuo Zhou, Zhikai Zhu, Kai Zhang, Kejun Bu, Chung-Kun Song, Haiyun Shu, Shuai Yan, Dongbo Wang, Wenge Yang, Gang Liu, Yanfeng Guo, Gang Liu
Layered semiconductors offer distinct advantages for optoelectronically responsive heterojunction devices due to their strong light–matter interactions and weak interlayer van der Waals interactions, which enable exfoliation into adjustable thicknesses. However, their practical utility is often restricted by excessively wide bandgaps, which limit spectral response within the visible light range and reduce light absorption efficiency, thereby constraining broadband detection capabilities. In this study, pressure was employed as a tuning parameter to modulate the bandgap and optimize the photoelectric performance of the layered semiconductor GeI2. Structural stability under moderate compression (5 GPa) was confirmed through in situ Raman spectra and x-ray diffraction, with no evidence of phase transition. At 5 GPa, a remarkable five-order-of-magnitude enhancement in photoelectric activity was observed. In situ UV-visible absorption spectroscopy, supported by theoretical calculations, revealed that this enhancement is primarily driven by pressure-induced narrowing of the bandgap. These findings offer critical insights for designing two-dimensional broadband photodetectors with tailored bandgap properties and enhanced photoelectric response, contributing to advancing next-generation flexible optoelectronic devices.
{"title":"Pressure-regulated bandgap narrowing and photoelectric activity enhancement in layered halide compound GeI2","authors":"Zhongyang Li, Yiming Wang, Xiaohui Zeng, Shuo Zhou, Zhikai Zhu, Kai Zhang, Kejun Bu, Chung-Kun Song, Haiyun Shu, Shuai Yan, Dongbo Wang, Wenge Yang, Gang Liu, Yanfeng Guo, Gang Liu","doi":"10.1063/5.0256512","DOIUrl":"https://doi.org/10.1063/5.0256512","url":null,"abstract":"Layered semiconductors offer distinct advantages for optoelectronically responsive heterojunction devices due to their strong light–matter interactions and weak interlayer van der Waals interactions, which enable exfoliation into adjustable thicknesses. However, their practical utility is often restricted by excessively wide bandgaps, which limit spectral response within the visible light range and reduce light absorption efficiency, thereby constraining broadband detection capabilities. In this study, pressure was employed as a tuning parameter to modulate the bandgap and optimize the photoelectric performance of the layered semiconductor GeI2. Structural stability under moderate compression (5 GPa) was confirmed through in situ Raman spectra and x-ray diffraction, with no evidence of phase transition. At 5 GPa, a remarkable five-order-of-magnitude enhancement in photoelectric activity was observed. In situ UV-visible absorption spectroscopy, supported by theoretical calculations, revealed that this enhancement is primarily driven by pressure-induced narrowing of the bandgap. These findings offer critical insights for designing two-dimensional broadband photodetectors with tailored bandgap properties and enhanced photoelectric response, contributing to advancing next-generation flexible optoelectronic devices.","PeriodicalId":14741,"journal":{"name":"Japanese Journal of Applied Physics","volume":"137 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.aip.org/aip/jap/article-pdf/doi/10.1063/5.0256512/20413829/085902_1_5.0256512.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147330778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-18DOI: 10.35848/1347-4065/ad7554
Xuefeng Xiao, Yan Huang, Yan Zhang, Jiashun Si, Shuaijie Liang, Qingyan Xu, Huan Zhang, Lingling Ma, Cui Yang, Xuefeng Zhang, Jiayue Xu, Tian Tian and Hui Shen
This paper is based on the first principles of density functional theory and uses the virtual crystal approximation method to calculate and analyze the optical properties of differently proportioned Eu3+-doped Bismuth silicate (Bi4Si3O12, or BSO). The results show that minor Eu3+ doping (1/12–1/3) improves the polarization ability of BSO and reduces energy loss. Additionally, doping an appropriate amount of Eu3+ (1/12–1/3) can improve light absorption and transmission of BSO to some extent. That is to say, Eu3+ doping improves the response of BSO to infrared light, and the absorption capacity in the ultraviolet and visible light regions is also enhanced. The theoretical research in this paper elucidates the changes in the optical properties of BSO after doping with Eu3+, providing a theoretical basis for expanding its application as a scintillation crystal in high-energy physics experiments, nuclear medicine, and other fields.
{"title":"Research on optical properties of Eu3+ doped bismuth silicate crystals based on first principles","authors":"Xuefeng Xiao, Yan Huang, Yan Zhang, Jiashun Si, Shuaijie Liang, Qingyan Xu, Huan Zhang, Lingling Ma, Cui Yang, Xuefeng Zhang, Jiayue Xu, Tian Tian and Hui Shen","doi":"10.35848/1347-4065/ad7554","DOIUrl":"https://doi.org/10.35848/1347-4065/ad7554","url":null,"abstract":"This paper is based on the first principles of density functional theory and uses the virtual crystal approximation method to calculate and analyze the optical properties of differently proportioned Eu3+-doped Bismuth silicate (Bi4Si3O12, or BSO). The results show that minor Eu3+ doping (1/12–1/3) improves the polarization ability of BSO and reduces energy loss. Additionally, doping an appropriate amount of Eu3+ (1/12–1/3) can improve light absorption and transmission of BSO to some extent. That is to say, Eu3+ doping improves the response of BSO to infrared light, and the absorption capacity in the ultraviolet and visible light regions is also enhanced. The theoretical research in this paper elucidates the changes in the optical properties of BSO after doping with Eu3+, providing a theoretical basis for expanding its application as a scintillation crystal in high-energy physics experiments, nuclear medicine, and other fields.","PeriodicalId":14741,"journal":{"name":"Japanese Journal of Applied Physics","volume":"36 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142247979","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-18DOI: 10.35848/1347-4065/ad6e96
Kohei Maruyama, Yoshihiro Kawakami and Fumio Narita
In this study, we employed corona poling to improve the piezoelectric properties of as-deposited BaTiO3 films and conducted a vibration energy harvesting test. Dielectric measurements indicated that the dielectric constant of the as-deposited film increased with temperature, and the frequency dependence of the dielectric constant was minimal at room temperature. Applying an electric field of 1500 kV cm−1 resulted in a recoverable energy density of 7.1 J cm−3 and an energy storage efficiency of 54%. The corona polarization treatment could align dipoles under high electric fields and prevent dielectric breakdown owing to local defects created by the aerosol deposition (AD) process. The vibration test yielded a harvested energy of 172 nJ and an output voltage of 2.67 V, which is suitable for force sensor applications. Polarization via corona discharge is also feasible without an electrode. Integrating AD with corona poling may benefit new capacitors, sensors, and energy harvesting technologies.
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