Interracial resistive switching of a ferroelectric semiconductor heterojunction is highly advantageous for the newly developed ferroelectric memristors. Moreover, the interfacial state in the ferroelectric semiconduct...Interracial resistive switching of a ferroelectric semiconductor heterojunction is highly advantageous for the newly developed ferroelectric memristors. Moreover, the interfacial state in the ferroelectric semiconductor heterojunction can be gradually modified by polarization reversal, which may give rise to continuously tunable resistive switching behavior. In this work, the interfacial state of a ferroelectric BiFeO3/Nb-doped SrTiO3 junction was modulated by ferroelectric polarization reversal. The dynamics of surface screening charges on the BiFeO3 layer was also investigated by surface potential measure- ments, and the decay of the surface potential could be speeded up by the magnetic field. Moreover, ferroelectric polarization reversal of the BiFeO3 layer was tuned by the magnetic field. This finding could provide a method to enhance the ferroelectric and electrical properties of ferroelectric BiFeO3 films by tuning the magnetic field.展开更多
Plasmonic metal-semiconductor nano-heterojuncfions （NHJs）, with their superior photocatalytic performance, provide opportunities for the efficient utilization of solar energy. However, scientific significance and te...Plasmonic metal-semiconductor nano-heterojuncfions （NHJs）, with their superior photocatalytic performance, provide opportunities for the efficient utilization of solar energy. However, scientific significance and technical challenges remain in the development of suitable metal-semiconductor NHJ photoelectrodes for new generation flexible optoelectronic devices, which often require complex processing. Herein, we report integrated three-dimensional （3D） NHJ photoelectrodes by conformally coating cadmium sulfide （CdS） nanolayers onto ultrathin nano- porous gold （NPG） films via a facile electrodeposition method. Localized surface plasmon resonance （LSPR） of NPG enhances the electron-hole pair generation and separation. Moreover, the direct contact interface and high conductive framework structure of the NHJs boosts the photogenerated carrier separation and transport. Hence, the NHJs exhibit evidently enhanced photocurrent density and hydrogen evolution rate relative to CdS deposited on either gold （Au） foil or fluorine-doped tin oxide （FTO） at 0 V vs. SCE （saturated calomel electrode） under visible-light irradiation. Moreover, they demonstrate a surprisingly stable photoelectrochemical hydrogen evolution （PEC-HE） activity over 104 s of continuous irradiation.展开更多
The spin current in a parabolically confined semiconductor hcterojunction quantum wire with Drcsselhaus spinorbit coupling is theoretically studied by using the perturbation method. The formulae of the elements for li...The spin current in a parabolically confined semiconductor hcterojunction quantum wire with Drcsselhaus spinorbit coupling is theoretically studied by using the perturbation method. The formulae of the elements for linear and angular spin current densities are derived by using the recent definition for spin current based on spin continuity equation. It is found that the spin current in this Dresselhaus spin-orbit coupling quantum wire is antisymmetrical, which is different from that in Rashba model due to the difference in symmetry between these two models. Some numerical examples for the result are also demonstrated and discussed.展开更多
基金This work was supported by the National Natural Science Foundation of China （Grant, No. 11574365）.
文摘Interracial resistive switching of a ferroelectric semiconductor heterojunction is highly advantageous for the newly developed ferroelectric memristors. Moreover, the interfacial state in the ferroelectric semiconductor heterojunction can be gradually modified by polarization reversal, which may give rise to continuously tunable resistive switching behavior. In this work, the interfacial state of a ferroelectric BiFeO3/Nb-doped SrTiO3 junction was modulated by ferroelectric polarization reversal. The dynamics of surface screening charges on the BiFeO3 layer was also investigated by surface potential measure- ments, and the decay of the surface potential could be speeded up by the magnetic field. Moreover, ferroelectric polarization reversal of the BiFeO3 layer was tuned by the magnetic field. This finding could provide a method to enhance the ferroelectric and electrical properties of ferroelectric BiFeO3 films by tuning the magnetic field.
基金This work was financially supported by the National Natural Science Foundation of China （No. 51671145）, the National Thousand Young Talents Program of China, the Tianjin Municipal Education Commission, the Tianjin Munidpal Science and Technology Commission （No. 16JCYBJC17000） and the Fundamental Research Funds of Tianjin University of Technology. We would like to thank Dr. Anna Carlsson from FEI Company for her assistance with the atomic-resolution structure and EELS analyses, and Y. D. also acknowledges useful discussions and experimental assistance from Dr. Yajun Gao, Dr. Rongyue Wang, Dr. Chuancheng Jia, Xuanxuan Bi, and Junli Liu.
文摘Plasmonic metal-semiconductor nano-heterojuncfions （NHJs）, with their superior photocatalytic performance, provide opportunities for the efficient utilization of solar energy. However, scientific significance and technical challenges remain in the development of suitable metal-semiconductor NHJ photoelectrodes for new generation flexible optoelectronic devices, which often require complex processing. Herein, we report integrated three-dimensional （3D） NHJ photoelectrodes by conformally coating cadmium sulfide （CdS） nanolayers onto ultrathin nano- porous gold （NPG） films via a facile electrodeposition method. Localized surface plasmon resonance （LSPR） of NPG enhances the electron-hole pair generation and separation. Moreover, the direct contact interface and high conductive framework structure of the NHJs boosts the photogenerated carrier separation and transport. Hence, the NHJs exhibit evidently enhanced photocurrent density and hydrogen evolution rate relative to CdS deposited on either gold （Au） foil or fluorine-doped tin oxide （FTO） at 0 V vs. SCE （saturated calomel electrode） under visible-light irradiation. Moreover, they demonstrate a surprisingly stable photoelectrochemical hydrogen evolution （PEC-HE） activity over 104 s of continuous irradiation.
基金Project supported by the National Natural Science Foundation of China （Grant No 10574042） and the Scientific Research Fund of Hunan Provincial Education Department （Grant No 04A031）.
文摘The spin current in a parabolically confined semiconductor hcterojunction quantum wire with Drcsselhaus spinorbit coupling is theoretically studied by using the perturbation method. The formulae of the elements for linear and angular spin current densities are derived by using the recent definition for spin current based on spin continuity equation. It is found that the spin current in this Dresselhaus spin-orbit coupling quantum wire is antisymmetrical, which is different from that in Rashba model due to the difference in symmetry between these two models. Some numerical examples for the result are also demonstrated and discussed.
