Superconducting diodes,which enable dissipationless supercurrent flow in one direction while blocking it in the reverse direction,are emerging as pivotal components for superconducting electronics.The development of e...Superconducting diodes,which enable dissipationless supercurrent flow in one direction while blocking it in the reverse direction,are emerging as pivotal components for superconducting electronics.The development of editable superconducting diodes could unlock transformative applications,including dynamically reconfigurable quantum circuits that adapt to operational requirements.Here,we report the first observation of the superconducting diode effect(SDE)in LaAlO_(3)/KTaO_(3) heterostructures—a two-dimensional oxide interface superconductor with exceptional tunability.We observe a strong SDE in Hall-bar(or strip-shaped)devices under perpendicular magnetic fields(<15 Oe),with efficiencies above 40%and rectification signals exceeding 10 mV.Through conductive atomic force microscope lithography,we demonstrate reversible nanoscale editing of the SDE’s polarity and efficiency by locally modifying the superconducting channel edges.This approach enables multiple nonvolatile configurations within a single device,realizing an editable superconducting diode.Our work establishes LaAlO_(3)/KTaO_(3) as a platform for vortex-based nonreciprocal transport and provides a pathway toward designer quantum circuits with on-demand functionalities.展开更多
Owing to superior breakdown voltage and excellent robustness,the betagallium oxide(β-Ga_(2)O_(3))power device has emerged as a pivotal research frontier in power electronics.Although advanced packaging strategies,inc...Owing to superior breakdown voltage and excellent robustness,the betagallium oxide(β-Ga_(2)O_(3))power device has emerged as a pivotal research frontier in power electronics.Although advanced packaging strategies,including nanosilver paste sintering,alumina direct bond copper(DBC)substrates,and flipchip structures,have been adopted to mitigate the intrinsic low thermal conductivity ofβ-Ga_(2)O_(3).However,a further reduction in the thermal resistance while maintaining high reliability remains a challenge.This study introduces a novel packaging methodology that synergistically integrates nano-silver films with aluminum nitride active metal brazing(AMB-AlN)substrates,achieving an ultra-low junction-to-case thermal resistance.By comprehensive reliability assessments onβ-Ga_(2)O_(3) Schottky barrier diodes(SBDs)and hetero-junction diodes(HJDs),the results demonstrate that the SBDs and HJDs exhibit surge current densities of 0.876 kA/cm^(2) and 0.778 kA/cm^(2),respectively,which represents a significant advancement in device performance benchmarks.These advancements provide critical insights into packaging design for highreliability ultrawide bandgap semiconductor systems.展开更多
This study presents aβ-Ga_(2)O_(3)diode featuring a Fin-channel structure and an anode ohmic contact.The device turnoff is facilitated by the depletion effect induced by the work function difference between the sidew...This study presents aβ-Ga_(2)O_(3)diode featuring a Fin-channel structure and an anode ohmic contact.The device turnoff is facilitated by the depletion effect induced by the work function difference between the sidewall metal andβ-Ga_(2)O_(3).As the forward bias increases,electron accumulation occurs on the Fin-channel sidewalls,reducing the on-resistance and improving the forward characteristics.Moreover,the device exhibits the reduced surface field(RESURF)effect,similar to trench schottky barrier diodes(SBDs),which shifts the electric field at the fin corners and enhances the breakdown voltage.For a device with a 100 nm fin width(W_(fin)),we achieved a breakdown voltage(BV)of 1137 V,a specific on-resistance(R_(on,sp))of 1.8 mΩ·cm^(2),and a power figure of merit(PFOM)of 0.72 GW/cm^(2).This work expands the fabrication approach forβ-Ga_(2)O_(3)-based devices,advancing their potential for high-performance applications.展开更多
氮化铝镓(AlGaN)与氮化铝(AlN)属于第三代半导体材料,广泛应用于发光二极管(LED)和功率电子器件领域。金属有机化学气相沉积(Metal-organic Chemical Vapor Deposition,MOCVD)是制备这些半导体材料的关键。当应用预混喷淋式MOCVD时,在...氮化铝镓(AlGaN)与氮化铝(AlN)属于第三代半导体材料,广泛应用于发光二极管(LED)和功率电子器件领域。金属有机化学气相沉积(Metal-organic Chemical Vapor Deposition,MOCVD)是制备这些半导体材料的关键。当应用预混喷淋式MOCVD时,在高温条件下,预反应会对薄膜的均匀性产生不利影响,降低混合腔的温度可以解决这个问题。对混合腔下盘、喷淋口上盘和盘体组成的通道进行冷却,可以使混合腔处于低温状态。笔者对原有冷却通道进行分析,发现温度分布均匀性较差。为了解决以上问题,本文提出多扇区通道冷却和多平行通道冷却方式,研究结果表明,八扇区B模型可以更好地冷却混合腔,冷却均匀性更高。展开更多
In this paper,we present a circuit model of single-quantum-well InGaN/GaN light-emitting diodes based on the standard rate equations.Two rate equations describe carrier transport processes occurring in sep-arate confi...In this paper,we present a circuit model of single-quantum-well InGaN/GaN light-emitting diodes based on the standard rate equations.Two rate equations describe carrier transport processes occurring in sep-arate confinement heterostructure and quantum well respectively,and the third equation describes the varied photons in quantum well.By using the presented model,impacts of quantum well thickness on the static and dynamic performances are investigated.Simulated results show that LED with 4 nm well exhibits better lightcurrent(L-I)performance,but LED with 3 nm well presents wider 3 dB modulation bandwidth.It reveals that high carrier density in quantum well is detrimental to the static performance,but beneficial to the dynamic performance.展开更多
基金supported by the National Key R&D Program of China (Grant No.2023YFA1406400)the National Natural Science Foundation of China (Grant Nos.12534005 and 12325402)。
文摘Superconducting diodes,which enable dissipationless supercurrent flow in one direction while blocking it in the reverse direction,are emerging as pivotal components for superconducting electronics.The development of editable superconducting diodes could unlock transformative applications,including dynamically reconfigurable quantum circuits that adapt to operational requirements.Here,we report the first observation of the superconducting diode effect(SDE)in LaAlO_(3)/KTaO_(3) heterostructures—a two-dimensional oxide interface superconductor with exceptional tunability.We observe a strong SDE in Hall-bar(or strip-shaped)devices under perpendicular magnetic fields(<15 Oe),with efficiencies above 40%and rectification signals exceeding 10 mV.Through conductive atomic force microscope lithography,we demonstrate reversible nanoscale editing of the SDE’s polarity and efficiency by locally modifying the superconducting channel edges.This approach enables multiple nonvolatile configurations within a single device,realizing an editable superconducting diode.Our work establishes LaAlO_(3)/KTaO_(3) as a platform for vortex-based nonreciprocal transport and provides a pathway toward designer quantum circuits with on-demand functionalities.
文摘Owing to superior breakdown voltage and excellent robustness,the betagallium oxide(β-Ga_(2)O_(3))power device has emerged as a pivotal research frontier in power electronics.Although advanced packaging strategies,including nanosilver paste sintering,alumina direct bond copper(DBC)substrates,and flipchip structures,have been adopted to mitigate the intrinsic low thermal conductivity ofβ-Ga_(2)O_(3).However,a further reduction in the thermal resistance while maintaining high reliability remains a challenge.This study introduces a novel packaging methodology that synergistically integrates nano-silver films with aluminum nitride active metal brazing(AMB-AlN)substrates,achieving an ultra-low junction-to-case thermal resistance.By comprehensive reliability assessments onβ-Ga_(2)O_(3) Schottky barrier diodes(SBDs)and hetero-junction diodes(HJDs),the results demonstrate that the SBDs and HJDs exhibit surge current densities of 0.876 kA/cm^(2) and 0.778 kA/cm^(2),respectively,which represents a significant advancement in device performance benchmarks.These advancements provide critical insights into packaging design for highreliability ultrawide bandgap semiconductor systems.
基金supported in part by the National Key Research and Development Program of China(Grant No.2021YFC2203400)Key Laboratory Construction Project of Nanchang(Grant No.2020-NCZDSY-008)+1 种基金Jiangxi Province Double Thousand Plan (Grant No. S2019CQKJ2638)in part the National Natural Science Foundation of China(Grant Nos.62074053).
文摘This study presents aβ-Ga_(2)O_(3)diode featuring a Fin-channel structure and an anode ohmic contact.The device turnoff is facilitated by the depletion effect induced by the work function difference between the sidewall metal andβ-Ga_(2)O_(3).As the forward bias increases,electron accumulation occurs on the Fin-channel sidewalls,reducing the on-resistance and improving the forward characteristics.Moreover,the device exhibits the reduced surface field(RESURF)effect,similar to trench schottky barrier diodes(SBDs),which shifts the electric field at the fin corners and enhances the breakdown voltage.For a device with a 100 nm fin width(W_(fin)),we achieved a breakdown voltage(BV)of 1137 V,a specific on-resistance(R_(on,sp))of 1.8 mΩ·cm^(2),and a power figure of merit(PFOM)of 0.72 GW/cm^(2).This work expands the fabrication approach forβ-Ga_(2)O_(3)-based devices,advancing their potential for high-performance applications.
文摘氮化铝镓(AlGaN)与氮化铝(AlN)属于第三代半导体材料,广泛应用于发光二极管(LED)和功率电子器件领域。金属有机化学气相沉积(Metal-organic Chemical Vapor Deposition,MOCVD)是制备这些半导体材料的关键。当应用预混喷淋式MOCVD时,在高温条件下,预反应会对薄膜的均匀性产生不利影响,降低混合腔的温度可以解决这个问题。对混合腔下盘、喷淋口上盘和盘体组成的通道进行冷却,可以使混合腔处于低温状态。笔者对原有冷却通道进行分析,发现温度分布均匀性较差。为了解决以上问题,本文提出多扇区通道冷却和多平行通道冷却方式,研究结果表明,八扇区B模型可以更好地冷却混合腔,冷却均匀性更高。
文摘In this paper,we present a circuit model of single-quantum-well InGaN/GaN light-emitting diodes based on the standard rate equations.Two rate equations describe carrier transport processes occurring in sep-arate confinement heterostructure and quantum well respectively,and the third equation describes the varied photons in quantum well.By using the presented model,impacts of quantum well thickness on the static and dynamic performances are investigated.Simulated results show that LED with 4 nm well exhibits better lightcurrent(L-I)performance,but LED with 3 nm well presents wider 3 dB modulation bandwidth.It reveals that high carrier density in quantum well is detrimental to the static performance,but beneficial to the dynamic performance.
