Based on the self-terminating thermal oxidation-assisted wet etching technique,two kinds of enhancement mode Al_(2)O_(3)/GaN MOSFETs(metal-oxide-semiconductor field-effect transistors)separately with sapphire substrat...Based on the self-terminating thermal oxidation-assisted wet etching technique,two kinds of enhancement mode Al_(2)O_(3)/GaN MOSFETs(metal-oxide-semiconductor field-effect transistors)separately with sapphire substrate and Si sub-strate are prepared.It is found that the performance of sapphire substrate device is better than that of silicon substrate.Comparing these two devices,the maximum drain current of sapphire substrate device(401 mA/mm)is 1.76 times that of silicon substrate device(228 mA/mm),and the field-effect mobility(μ_(FEmax))of sapphire substrate device(176 cm^(2)/V·s)is 1.83 times that of silicon substrate device(96 cm^(2)/V·s).The conductive resistance of silicon substrate device is 21.2Ω-mm,while that of sapphire substrate device is only 15.2Ω·mm,which is 61%that of silicon substrate device.The significant difference in performance between sapphire substrate and Si substrate is related to the differences in interface and border trap near Al_(2)O_(3)/GaN interface.Experimental studies show that(i)interface/border trap density in the sapphire substrate device is one order of magnitude lower than in the Si substrate device,(ii)Both the border traps in Al_(2)O_(3) dielectric near Al_(2)O_(3)/GaN and the interface traps in Al_(2)O_(3)/GaN interface have a significantly effect on device channel mobility,and(iii)the properties of gallium nitride materials on different substrates are different due to wet etching.The research results in this work provide a reference for further optimizing the performances of silicon substrate devices.展开更多
Electrolyzing seawater to produce hydrogen can not only address the issue of freshwater scarcity but also provide an abundant raw material for hydrogen production.However,seawater electrolysis for hydrogen production ...Electrolyzing seawater to produce hydrogen can not only address the issue of freshwater scarcity but also provide an abundant raw material for hydrogen production.However,seawater electrolysis for hydrogen production still faces numerous risks and challenges at present.This study focuses on a systematic investigation of FeNiCo-based highentropy alloy(HEA)nanocatalysts supported on carbon skeletons.By precisely regulating the morphological structure of the carbon skeleton,a carbon support with a large specific surface area and abundant active sites can be obtained.Simultaneously,the elemental composition of the HEA nanoparticles is adjusted to optimize its seawater electrolysis performance.An energy-saving strategy of coupling the anode sulfur oxidation reaction(SOR)with the cathode hydrogen evolution reaction(HER)is employed to assist seawater electrolysis.In alkaline seawater,at a current density of 10 mA·cm^(−2),the overpotential of the HER is only 22 mV,and the overpotential of the oxygen evolution reaction(OER)is 264 mV.It also exhibits excellent performance in acidic seawater.In a two-electrode seawater electrolysis system,an applied voltage of 1.55 V is required to reach a current density of 10 mA·cm^(−2).More importantly,when using SOR to assist alkaline seawater electrolysis,the applied voltage is successfully reduced to 0.82 V.展开更多
基金Project supported by the Research on Key Techniques in Reliability of Low Power Sensor Chip for IOTIPS and the Technology Project of Headquarters,State Grid Corporation of China(Grant No.5700-202041397A-0-0-00).
文摘Based on the self-terminating thermal oxidation-assisted wet etching technique,two kinds of enhancement mode Al_(2)O_(3)/GaN MOSFETs(metal-oxide-semiconductor field-effect transistors)separately with sapphire substrate and Si sub-strate are prepared.It is found that the performance of sapphire substrate device is better than that of silicon substrate.Comparing these two devices,the maximum drain current of sapphire substrate device(401 mA/mm)is 1.76 times that of silicon substrate device(228 mA/mm),and the field-effect mobility(μ_(FEmax))of sapphire substrate device(176 cm^(2)/V·s)is 1.83 times that of silicon substrate device(96 cm^(2)/V·s).The conductive resistance of silicon substrate device is 21.2Ω-mm,while that of sapphire substrate device is only 15.2Ω·mm,which is 61%that of silicon substrate device.The significant difference in performance between sapphire substrate and Si substrate is related to the differences in interface and border trap near Al_(2)O_(3)/GaN interface.Experimental studies show that(i)interface/border trap density in the sapphire substrate device is one order of magnitude lower than in the Si substrate device,(ii)Both the border traps in Al_(2)O_(3) dielectric near Al_(2)O_(3)/GaN and the interface traps in Al_(2)O_(3)/GaN interface have a significantly effect on device channel mobility,and(iii)the properties of gallium nitride materials on different substrates are different due to wet etching.The research results in this work provide a reference for further optimizing the performances of silicon substrate devices.
基金supported by the Guangxi Natural Science Fund for Distinguished Young Scholars(2024GXNSFFA010008)the National Natural Science Foundation of China(22469002)+1 种基金Guangxi Chongzuo Science and Technology Plan Youth Project(Chongke 2023QN045658)School-level scientific research youth project of Guangxi Normal University for Nationalities(2022QN058).
文摘Electrolyzing seawater to produce hydrogen can not only address the issue of freshwater scarcity but also provide an abundant raw material for hydrogen production.However,seawater electrolysis for hydrogen production still faces numerous risks and challenges at present.This study focuses on a systematic investigation of FeNiCo-based highentropy alloy(HEA)nanocatalysts supported on carbon skeletons.By precisely regulating the morphological structure of the carbon skeleton,a carbon support with a large specific surface area and abundant active sites can be obtained.Simultaneously,the elemental composition of the HEA nanoparticles is adjusted to optimize its seawater electrolysis performance.An energy-saving strategy of coupling the anode sulfur oxidation reaction(SOR)with the cathode hydrogen evolution reaction(HER)is employed to assist seawater electrolysis.In alkaline seawater,at a current density of 10 mA·cm^(−2),the overpotential of the HER is only 22 mV,and the overpotential of the oxygen evolution reaction(OER)is 264 mV.It also exhibits excellent performance in acidic seawater.In a two-electrode seawater electrolysis system,an applied voltage of 1.55 V is required to reach a current density of 10 mA·cm^(−2).More importantly,when using SOR to assist alkaline seawater electrolysis,the applied voltage is successfully reduced to 0.82 V.
