With the rapid advancement of optoelectronic technology,high-performance photodetectors are increasingly in demand in fields such as environmental monitoring,optical communication,and defense systems,where ultraviolet...With the rapid advancement of optoelectronic technology,high-performance photodetectors are increasingly in demand in fields such as environmental monitoring,optical communication,and defense systems,where ultraviolet detection is critical.However,conventional semiconductor materials suffer from limited UV-visible detection capabilities owing to their narrow bandgaps and high dark currents.To address these challenges,wide-bandgap semiconductors have emerged as promising alternatives.Here,we fabricated a horizontally structured n–n heterojunction photodetector by growingβ-Ga_(2)O_(3) on Si–GaN via plasma-enhanced chemical vapor deposition.The device exhibits a self-powered photocurrent of 3.5 nA at zero bias,enabled by the photovoltaic effect of the space charge region.Under 254-nm and 365-nm illumination,it exhibits rectification behavior,achieving a responsivity of 0.475 m A/W(0 V,220??W/cm~2 at 254 nm)and 257.6 mA/W(-5 V),respectively.Notably,the photodetector demonstrates a high photocurrent-to-dark current ratio of 10~5 under-5-V bias,highlighting its potential for self-powered and high-performance UV detection applications.展开更多
Any product must undergo precise manufacturing before use.The damage incurred during the manufacturing process can significantly impact the residual strength of the product post-manufacturing.However,the relationship ...Any product must undergo precise manufacturing before use.The damage incurred during the manufacturing process can significantly impact the residual strength of the product post-manufacturing.However,the relationship between residual bending strength and manufacturing-induced damage remains unclear,despite being a crucial parameter for assessing material service life and performance,leading to a decrease in product performance reliability.This study focuses on investigating the impact of crack generation on residual bending strength through theoretical and experimental analyses of scratching,grinding,and three-point bending.The research first elucidates the forms and mechanisms of material damage through scratch experiments.Subsequently,using resin-bonded and electroplated wheels as case studies,the influence of different process parameters on grinding damage and residual bending strength is explored.The reduction of brittle removal can lead to a 50%–60%decrease in residual bending strength.Lastly,a model is developed to delineate the relationship between processing parameters and the residual bending strength of the product,with the model exhibiting an error margin of less than 11%.This model clearly reveals the effect of crack generation under different process parameters on residual flexural strength.展开更多
A series of Eu^(2+)/Eu^(3+)doped 20La_(2)O_(3)-20Al_(2)O_(3)-60SiO_(2)glasses(LAS:Eu)were fabricated via melting quenching method in air atmosphere.By introducing the reducing agent Si_(3)N_(4),the ratio of Eu^(2+)/Eu...A series of Eu^(2+)/Eu^(3+)doped 20La_(2)O_(3)-20Al_(2)O_(3)-60SiO_(2)glasses(LAS:Eu)were fabricated via melting quenching method in air atmosphere.By introducing the reducing agent Si_(3)N_(4),the ratio of Eu^(2+)/Eu^(3+)in glasses can be controlled under atmospheric conditions at 1520℃for 5 h.As the tunable Eu^(2+)/Eu^(3+)component in LAS:Eu glasses,the wavelength conversion of photoluminescence is achieved upon the395 nm excitation,where LAS:0.7Eu exhibits a color coordinate of(0.334,0.314).According to calculation,the energy transfer mechanism between Eu^(2+)and Eu^(3+)in glasses is dipole-dipole interactions dominate.Meanwhile,relative X-ray excited luminescence(XEL)intensity of the single Eu^(2+)doped glass can reach 38.6%of that of Bi_(4)Ge_(3)O_(12)(BGO)crystal.The temperature-dependent emission spectra of the LAS:Eu glasses were tested under photoluminescence and X-ray excitation,and the thermal activation energy was calculated.These results demonstrate the potential of LAS:Eu glass for applications as lightemitting diode(LED)materials and scintillators in nuclear radiation detection.展开更多
基金Project supported by the Joints Fund of the National Natural Science Foundation of China(Grant No.U23A20349)the Young Scientists Fund of the National Natural Science Foundation of China(Grant Nos.62204126,62305171,62304113)。
文摘With the rapid advancement of optoelectronic technology,high-performance photodetectors are increasingly in demand in fields such as environmental monitoring,optical communication,and defense systems,where ultraviolet detection is critical.However,conventional semiconductor materials suffer from limited UV-visible detection capabilities owing to their narrow bandgaps and high dark currents.To address these challenges,wide-bandgap semiconductors have emerged as promising alternatives.Here,we fabricated a horizontally structured n–n heterojunction photodetector by growingβ-Ga_(2)O_(3) on Si–GaN via plasma-enhanced chemical vapor deposition.The device exhibits a self-powered photocurrent of 3.5 nA at zero bias,enabled by the photovoltaic effect of the space charge region.Under 254-nm and 365-nm illumination,it exhibits rectification behavior,achieving a responsivity of 0.475 m A/W(0 V,220??W/cm~2 at 254 nm)and 257.6 mA/W(-5 V),respectively.Notably,the photodetector demonstrates a high photocurrent-to-dark current ratio of 10~5 under-5-V bias,highlighting its potential for self-powered and high-performance UV detection applications.
基金Supported by National Key Research and Development Program of China(Grant No.2023YFB3711100)National Natural Science Foundation of China(Grant Nos.52275458,52275207)Tianjin Municipal Natural Science Foundation(Grant No.22JCZDJC00050)。
文摘Any product must undergo precise manufacturing before use.The damage incurred during the manufacturing process can significantly impact the residual strength of the product post-manufacturing.However,the relationship between residual bending strength and manufacturing-induced damage remains unclear,despite being a crucial parameter for assessing material service life and performance,leading to a decrease in product performance reliability.This study focuses on investigating the impact of crack generation on residual bending strength through theoretical and experimental analyses of scratching,grinding,and three-point bending.The research first elucidates the forms and mechanisms of material damage through scratch experiments.Subsequently,using resin-bonded and electroplated wheels as case studies,the influence of different process parameters on grinding damage and residual bending strength is explored.The reduction of brittle removal can lead to a 50%–60%decrease in residual bending strength.Lastly,a model is developed to delineate the relationship between processing parameters and the residual bending strength of the product,with the model exhibiting an error margin of less than 11%.This model clearly reveals the effect of crack generation under different process parameters on residual flexural strength.
基金Project supported by"Pioneer"and"Leading Goose"R&D Program of Zhejiang(2022C01046)the National Natural Science Foundation of China(12375183,61505193,12275262,11975220,51972291)Natural Science Foundation of Zhejiang(LGG22E020001)。
文摘A series of Eu^(2+)/Eu^(3+)doped 20La_(2)O_(3)-20Al_(2)O_(3)-60SiO_(2)glasses(LAS:Eu)were fabricated via melting quenching method in air atmosphere.By introducing the reducing agent Si_(3)N_(4),the ratio of Eu^(2+)/Eu^(3+)in glasses can be controlled under atmospheric conditions at 1520℃for 5 h.As the tunable Eu^(2+)/Eu^(3+)component in LAS:Eu glasses,the wavelength conversion of photoluminescence is achieved upon the395 nm excitation,where LAS:0.7Eu exhibits a color coordinate of(0.334,0.314).According to calculation,the energy transfer mechanism between Eu^(2+)and Eu^(3+)in glasses is dipole-dipole interactions dominate.Meanwhile,relative X-ray excited luminescence(XEL)intensity of the single Eu^(2+)doped glass can reach 38.6%of that of Bi_(4)Ge_(3)O_(12)(BGO)crystal.The temperature-dependent emission spectra of the LAS:Eu glasses were tested under photoluminescence and X-ray excitation,and the thermal activation energy was calculated.These results demonstrate the potential of LAS:Eu glass for applications as lightemitting diode(LED)materials and scintillators in nuclear radiation detection.
