Developing a heterostructure for alloying-based anode for sodium-ion batteries(SIBs)is an efficient solution to accommodate volume change upon sodiation/desodiation and boost sodium storage since it combines the merit...Developing a heterostructure for alloying-based anode for sodium-ion batteries(SIBs)is an efficient solution to accommodate volume change upon sodiation/desodiation and boost sodium storage since it combines the merits of each component.Herein,we report a metallic and microphone-like Sn-Zn_(0.9)Mn_(0.1)O heterostructure via an in-situ Mn doping strategy.Based on theoretical calculations and experimental results,the introduction of Mn into Zn O(a small amount of Mn also diffuses into the Sn lattice)can not only enhance intrinsic electronic conductivity but also reduce the Na^(+)diffusion barrier inside the Sn phase.When evaluated as anode for SIBs,the obtained heterostructures show a high reversible capacity of 395.1 mAh/g at 0.1 A/g,rate capability of 332 mAh/g at 5 A/g,and capacity retention of almost 100%after 850 cycles at 5 A/g,indicating its great potential for high-power application of SIBs.展开更多
We report a theoretical study of a broadband Si/graded-SiGe/Ge/Ge0.9Sn0.1 p–i–n photodetector with a flat response based on modulating thickness of the layers in the active region.The responsivity of the photodetect...We report a theoretical study of a broadband Si/graded-SiGe/Ge/Ge0.9Sn0.1 p–i–n photodetector with a flat response based on modulating thickness of the layers in the active region.The responsivity of the photodetector is about 0.57 A/W in the range of 700 to 1800 nm.This structure is suitable for silicon-based epitaxial growth.Annealing is technically applied to form the graded-SiGe.The photodetector reaches a cut-off wavelength at^2300 nm and a low dark-current density under 3 V reverse bias about 0.17 mA/cm^2 is achieved theoretical at room temperature.This work is of great significance for silicon-based detection and communication,from visible to infrared.展开更多
Thick-film thermistor with negative temperature coefficient（NTC）, low room-temperature resistivity and modest thermistor constant was screen-printed on the alumina substrate by the combination of 30.94III0.04II0.02 ...Thick-film thermistor with negative temperature coefficient（NTC）, low room-temperature resistivity and modest thermistor constant was screen-printed on the alumina substrate by the combination of 30.94III0.04II0.02 B OBi Coa Co with Ba0.5Bi0.5Fe0.9Sn0.1O3. The electrical properties of the thick films were characterized by a digital multimeter, a Keithley 2400 and an impedance analyzer. The results show that with the Ba0.5Bi0.5Fe0.9Sn0.1O3 content increasing from 0.05 to 0.25, the values of room-temperature resistivity, thermistor constant and peak voltage of the thick films increases and are in the ranges of 1.47-26.5 ？·cm, 678-1345 K and 18.9-47.0 V, respectively. The corresponding current at the peak voltage of the thick films decreases and is in the range of 40-240 m A. The impedance spectroscopy measurement demonstrates that the as-prepared thick films show the abnormal electrical heterogeneous microstructure, consisting of high-resistive grains and less resistive grain boundary regions. It can be concluded that the addition of Ba0.5Bi0.5Fe0.9Sn0.1O3 into 30.94III0.04II0.02 Ba Co OBi Co improves the thermistor behavior and but also deteriorates the current characteristics.展开更多
The humidity sensing properties of La^3＋ and K^＋ co-doped Ti0.9Sn0.1O2 thin films were investigated. The humidity sensitive thin films were prepared by sol-gel method on alumina substrates. The sensing behaviors of ...The humidity sensing properties of La^3＋ and K^＋ co-doped Ti0.9Sn0.1O2 thin films were investigated. The humidity sensitive thin films were prepared by sol-gel method on alumina substrates. The sensing behaviors of thin films were inspected at different sintering temperatures by constructing a humidity-impedance measuring system. It was found that the addition of rare earth ion La^3＋ and alkali ion K^＋ was beneficial for improving the humidity sensitive properties of the samples and La0.003K0.5Ti0.9Sn0.1O2 sintered at 500 ℃ for 4 h showed the best humidity sensing properties. The impedance of this thin film decreased from 109 to 104 Ω with excellent linearity in the humidity range of 11%-95%. Narrow hysteresis loop, prominent stability and high sensitivity were obtained. The effects of dopant con-tent and doping mechanism on humidity sensitivity were also discussed in terms of segregation of rare earth ions at grain boundaries and granularity of crystalline and influence of K^＋ on the decrease in the intrinsic resistance of the materials, and increase in the number of wa-ter adsorption sites.展开更多
基金financially supported by the National Natural Science Foundation of China(No.52072119)Hunan Provincial Natural Science Foundation(No.2023JJ50015)the 111 Project(No.D20015)。
文摘Developing a heterostructure for alloying-based anode for sodium-ion batteries(SIBs)is an efficient solution to accommodate volume change upon sodiation/desodiation and boost sodium storage since it combines the merits of each component.Herein,we report a metallic and microphone-like Sn-Zn_(0.9)Mn_(0.1)O heterostructure via an in-situ Mn doping strategy.Based on theoretical calculations and experimental results,the introduction of Mn into Zn O(a small amount of Mn also diffuses into the Sn lattice)can not only enhance intrinsic electronic conductivity but also reduce the Na^(+)diffusion barrier inside the Sn phase.When evaluated as anode for SIBs,the obtained heterostructures show a high reversible capacity of 395.1 mAh/g at 0.1 A/g,rate capability of 332 mAh/g at 5 A/g,and capacity retention of almost 100%after 850 cycles at 5 A/g,indicating its great potential for high-power application of SIBs.
基金This work was supported by National Basic Research Program of China(No.2013CB632103)National Natural Science Foundation of China(Nos.61534005 and 61474081)Scientific Research Project of Fujian Provincial Department of Education(No.JA15651).
文摘We report a theoretical study of a broadband Si/graded-SiGe/Ge/Ge0.9Sn0.1 p–i–n photodetector with a flat response based on modulating thickness of the layers in the active region.The responsivity of the photodetector is about 0.57 A/W in the range of 700 to 1800 nm.This structure is suitable for silicon-based epitaxial growth.Annealing is technically applied to form the graded-SiGe.The photodetector reaches a cut-off wavelength at^2300 nm and a low dark-current density under 3 V reverse bias about 0.17 mA/cm^2 is achieved theoretical at room temperature.This work is of great significance for silicon-based detection and communication,from visible to infrared.
基金Projects(5110205551462005)supported by the National Natural Science Foundation of China
文摘Thick-film thermistor with negative temperature coefficient（NTC）, low room-temperature resistivity and modest thermistor constant was screen-printed on the alumina substrate by the combination of 30.94III0.04II0.02 B OBi Coa Co with Ba0.5Bi0.5Fe0.9Sn0.1O3. The electrical properties of the thick films were characterized by a digital multimeter, a Keithley 2400 and an impedance analyzer. The results show that with the Ba0.5Bi0.5Fe0.9Sn0.1O3 content increasing from 0.05 to 0.25, the values of room-temperature resistivity, thermistor constant and peak voltage of the thick films increases and are in the ranges of 1.47-26.5 ？·cm, 678-1345 K and 18.9-47.0 V, respectively. The corresponding current at the peak voltage of the thick films decreases and is in the range of 40-240 m A. The impedance spectroscopy measurement demonstrates that the as-prepared thick films show the abnormal electrical heterogeneous microstructure, consisting of high-resistive grains and less resistive grain boundary regions. It can be concluded that the addition of Ba0.5Bi0.5Fe0.9Sn0.1O3 into 30.94III0.04II0.02 Ba Co OBi Co improves the thermistor behavior and but also deteriorates the current characteristics.
文摘The humidity sensing properties of La^3＋ and K^＋ co-doped Ti0.9Sn0.1O2 thin films were investigated. The humidity sensitive thin films were prepared by sol-gel method on alumina substrates. The sensing behaviors of thin films were inspected at different sintering temperatures by constructing a humidity-impedance measuring system. It was found that the addition of rare earth ion La^3＋ and alkali ion K^＋ was beneficial for improving the humidity sensitive properties of the samples and La0.003K0.5Ti0.9Sn0.1O2 sintered at 500 ℃ for 4 h showed the best humidity sensing properties. The impedance of this thin film decreased from 109 to 104 Ω with excellent linearity in the humidity range of 11%-95%. Narrow hysteresis loop, prominent stability and high sensitivity were obtained. The effects of dopant con-tent and doping mechanism on humidity sensitivity were also discussed in terms of segregation of rare earth ions at grain boundaries and granularity of crystalline and influence of K^＋ on the decrease in the intrinsic resistance of the materials, and increase in the number of wa-ter adsorption sites.
