A new ultra-low specific on-resistance （Ron,sp） vertical double diffusion metal-oxide-semiconductor field-effect tran- sistor （VDMOS） with continuous electron accumulation （CEA） layer, denoted as CEA-VDMOS, is p...A new ultra-low specific on-resistance （Ron,sp） vertical double diffusion metal-oxide-semiconductor field-effect tran- sistor （VDMOS） with continuous electron accumulation （CEA） layer, denoted as CEA-VDMOS, is proposed and its new current transport mechanism is investigated. It features a trench gate directly extended to the drain, which includes two PN junctions. In on-state, the electron accumulation layers are formed along the sides of the extended gate and introduce two continuous low-resistance current paths from the source to the drain in a cell pitch. This mechanism not only dramatically reduces the Ron,sp but also makes the Ron,sp almost independent of the n-pillar doping concentration （Am）. In off-state, the depletion between the n-pillar and p-pillar within the extended trench gate increases the Nn, and further reduces the Ron,sp. Especially, the two PNjunctions within the trench gate support a high gate--drain voltage in the off-state and on-state, re- spectively. However, the extended gate increases the gate capacitance and thus weakens the dynamic performance to some extent. Therefore, the CEA-VDMOS is more suitable for low and medium frequencies application. Simulation indicates that the CEA-VDMOS reduces the Ron,sp by 80% compared with the conventional super-junction VDMOS （CSJ-VDMOS） at the same high breakdown voltage （BV）.展开更多
During the water splitting process for hydrogen production with metal hydroxide electrocatalysts,a selfreconstructing reaction occurring at low potential is the key to efficient operation.In this work,a Ni-Fe(OH)3 ele...During the water splitting process for hydrogen production with metal hydroxide electrocatalysts,a selfreconstructing reaction occurring at low potential is the key to efficient operation.In this work,a Ni-Fe(OH)3 electrocatalyst is designed,in which the built-in electric field formed at the heterojunction results in electron accumulation on Ni and facilitates the reconstruction of Fe(OH)3 into active FeOOH under a lower applied potential while maintaining structural stability.Triggered by the interfacial electron accumulation and structural reconstruction,the prepared Ni-Fe(OH)_(3) anchored on an iron-nickel-foam substrate shows an overpotential of just 453 mV that can drive an ampere level current of 1.0 A cm^(−2) in 1.0 M KOH mixed seawater,with remarkable stability for over 360 h.Density functional theory calculations suggest that the in situ reconstructed Ni-FeOOH enhances the adsorption behavior of intermediates and significantly reduces the energy barrier of the oxygen evolution reaction.These results underscore the great promise of engineering a built-in electric field in transition metal hydroxide catalysts for efficient hydrogen production via seawater oxidation.展开更多
Optimizing charge migration and alleviating volume expansion in anode materials are the key to improve the electrochemical performance for sodium-ion storage devices.Herein,a hierarchical porous conducting matrix conf...Optimizing charge migration and alleviating volume expansion in anode materials are the key to improve the electrochemical performance for sodium-ion storage devices.Herein,a hierarchical porous conducting matrix confining defect-rich selenium doped cobalt dichalcogenide(CoSe_(0.5)S_(1.5)/GA)is constructed as a promising SICs anode based on the guidance of theoretical calculation analysis.The increased defect concentration significantly enhanced the disorder degree of the compound and presented electron aggregation around the S atoms,which effectively modulated the electronic structure,further enabling high rate and ultra-capacity sodium storage.Moreover,strong interfacial coupling could construct spatial constraint to alleviate volume expansion as well as maintain electrode integrity and stability.The CoSe_(0.5)S_(1.5)/GA electrode can deliver a high capacity of 310.1 mA h g^(-1)after 2000 cycles at 1 A g^(-1),and the CoSe_(0.5)S_(1.5)/GA//AC sodium ion capacitor can exhibit an outstanding energy density of 237.5 W h kg^(-1).A series of characterization and theoretical calculation convincingly reveal that the defect moieties can regulate the Na^(+)storage and diffusion kinetics,which prove that our defect manufacture coupling with space-confined strategy can provide deep insights into the development of high-performance Na^(+)storage devices.展开更多
Although CO_(2)photoreduction is a promising method for solar‐to‐fuel conversion,it suffers from low charge transfer efficiency of the photocatalysts.To improve the CO_(2)photoreduction performance,introduction of e...Although CO_(2)photoreduction is a promising method for solar‐to‐fuel conversion,it suffers from low charge transfer efficiency of the photocatalysts.To improve the CO_(2)photoreduction performance,introduction of electron‐accumulated materials on the photocatalyst surface is considered an effective method.In this study,the Bi_(19)S_(27)Br_(3)/BiOBr composites were designed and synthesized.The Bi19S27Br3 nanorod in this photocatalytic system acts as an electron‐accumulated active site for extracting the photogenerated electrons on the BiOBr surface and for effectively activating the CO2 molecules.As a result,Bi_(19)S_(27)Br_(3)/BiOBr composites exhibit the higher charge carrier transfer efficiency and further improves the CO_(2)photoreduction performance relative to that of pure Bi_(19)S_(27)Br_(3)and BiOBr.The rate of CO formation using Bi_(19)S_(27)Br_(3)/BiOBr‐5 is about 8.74 and 2.40 times that using Bi_(19)S_(27)Br_(3)and BiOBr,respectively.This work provides new insights for the application of Bi_(19)S_(27)Br_(3)as an electron‐accumulating site for achieving high photocatalytic CO2 reduction performance in the future.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.61176069 and 61376079)the Fundamental Research Funds for the Central Universities,China(Grant No.ZYGX2014Z006)
文摘A new ultra-low specific on-resistance （Ron,sp） vertical double diffusion metal-oxide-semiconductor field-effect tran- sistor （VDMOS） with continuous electron accumulation （CEA） layer, denoted as CEA-VDMOS, is proposed and its new current transport mechanism is investigated. It features a trench gate directly extended to the drain, which includes two PN junctions. In on-state, the electron accumulation layers are formed along the sides of the extended gate and introduce two continuous low-resistance current paths from the source to the drain in a cell pitch. This mechanism not only dramatically reduces the Ron,sp but also makes the Ron,sp almost independent of the n-pillar doping concentration （Am）. In off-state, the depletion between the n-pillar and p-pillar within the extended trench gate increases the Nn, and further reduces the Ron,sp. Especially, the two PNjunctions within the trench gate support a high gate--drain voltage in the off-state and on-state, re- spectively. However, the extended gate increases the gate capacitance and thus weakens the dynamic performance to some extent. Therefore, the CEA-VDMOS is more suitable for low and medium frequencies application. Simulation indicates that the CEA-VDMOS reduces the Ron,sp by 80% compared with the conventional super-junction VDMOS （CSJ-VDMOS） at the same high breakdown voltage （BV）.
基金supported by the National Natural Science Foundation of China(Grant No.21772152)the Key Research and Development Program of Shaanxi(2025CY-YBXM-029 and 2025CY-YBXM-033).
文摘During the water splitting process for hydrogen production with metal hydroxide electrocatalysts,a selfreconstructing reaction occurring at low potential is the key to efficient operation.In this work,a Ni-Fe(OH)3 electrocatalyst is designed,in which the built-in electric field formed at the heterojunction results in electron accumulation on Ni and facilitates the reconstruction of Fe(OH)3 into active FeOOH under a lower applied potential while maintaining structural stability.Triggered by the interfacial electron accumulation and structural reconstruction,the prepared Ni-Fe(OH)_(3) anchored on an iron-nickel-foam substrate shows an overpotential of just 453 mV that can drive an ampere level current of 1.0 A cm^(−2) in 1.0 M KOH mixed seawater,with remarkable stability for over 360 h.Density functional theory calculations suggest that the in situ reconstructed Ni-FeOOH enhances the adsorption behavior of intermediates and significantly reduces the energy barrier of the oxygen evolution reaction.These results underscore the great promise of engineering a built-in electric field in transition metal hydroxide catalysts for efficient hydrogen production via seawater oxidation.
基金financially supported by the National Nature Science Foundation of China(No.52202335)Natural Science Foundation of Jiangsu Province(No.BK20221137,BK20221139)。
文摘Optimizing charge migration and alleviating volume expansion in anode materials are the key to improve the electrochemical performance for sodium-ion storage devices.Herein,a hierarchical porous conducting matrix confining defect-rich selenium doped cobalt dichalcogenide(CoSe_(0.5)S_(1.5)/GA)is constructed as a promising SICs anode based on the guidance of theoretical calculation analysis.The increased defect concentration significantly enhanced the disorder degree of the compound and presented electron aggregation around the S atoms,which effectively modulated the electronic structure,further enabling high rate and ultra-capacity sodium storage.Moreover,strong interfacial coupling could construct spatial constraint to alleviate volume expansion as well as maintain electrode integrity and stability.The CoSe_(0.5)S_(1.5)/GA electrode can deliver a high capacity of 310.1 mA h g^(-1)after 2000 cycles at 1 A g^(-1),and the CoSe_(0.5)S_(1.5)/GA//AC sodium ion capacitor can exhibit an outstanding energy density of 237.5 W h kg^(-1).A series of characterization and theoretical calculation convincingly reveal that the defect moieties can regulate the Na^(+)storage and diffusion kinetics,which prove that our defect manufacture coupling with space-confined strategy can provide deep insights into the development of high-performance Na^(+)storage devices.
文摘Although CO_(2)photoreduction is a promising method for solar‐to‐fuel conversion,it suffers from low charge transfer efficiency of the photocatalysts.To improve the CO_(2)photoreduction performance,introduction of electron‐accumulated materials on the photocatalyst surface is considered an effective method.In this study,the Bi_(19)S_(27)Br_(3)/BiOBr composites were designed and synthesized.The Bi19S27Br3 nanorod in this photocatalytic system acts as an electron‐accumulated active site for extracting the photogenerated electrons on the BiOBr surface and for effectively activating the CO2 molecules.As a result,Bi_(19)S_(27)Br_(3)/BiOBr composites exhibit the higher charge carrier transfer efficiency and further improves the CO_(2)photoreduction performance relative to that of pure Bi_(19)S_(27)Br_(3)and BiOBr.The rate of CO formation using Bi_(19)S_(27)Br_(3)/BiOBr‐5 is about 8.74 and 2.40 times that using Bi_(19)S_(27)Br_(3)and BiOBr,respectively.This work provides new insights for the application of Bi_(19)S_(27)Br_(3)as an electron‐accumulating site for achieving high photocatalytic CO2 reduction performance in the future.
