This study used density functional theory and the quantum transport method to investigate the interfacial coupling and spin transport of transition metals(TMs)with a Fe,Co,and Ni/2H-VSe_(2)hybrid nanostructure.Because...This study used density functional theory and the quantum transport method to investigate the interfacial coupling and spin transport of transition metals(TMs)with a Fe,Co,and Ni/2H-VSe_(2)hybrid nanostructure.Because the indirect coupling of TM-Se-V led to an obvious reduction of the magnetic moment and the disappearance of the half-metal characteristics of 2H-VSe_(2),the expected spin-filtering effect of individual TMs and 2H-VSe_(2)deteriorated at the contact region.Nevertheless,all the TM/2H-VSe_(2)-based dual-probe devices exhibited an interesting bias-dependent spin-injection efficiency with a maximum output spin-polarized current of 666 mA mm-1 in Co/2H-VSe_(2).The proposed TM/2H-VSe_(2)-based spin-field-effect transistor demonstrated outstanding performance.The Ni/2H-VSe_(2)-based transistor achieved a maximum output spin-polarized current of 3117 m A mm-1 and demonstrated a good switching characteristic of 106 mV dec-1.Importantly,all transistors achieved a widely tunable scale of spin-extraction efficiency ranging consistently between 96%and-92%with gate bias.These results indicate a promising candidate for use in high-performance spintronic devices.展开更多
The conventional charge transport models based on density- and field-dependent mobility, only having a non-Arrhenius tem- perature dependence, cannot give good current-voltage characteristics of poly （2-methoxy-5-（2...The conventional charge transport models based on density- and field-dependent mobility, only having a non-Arrhenius tem- perature dependence, cannot give good current-voltage characteristics of poly （2-methoxy-5-（2＇-ethylhexyloxy）-p-phenylene vinylene） （MEH-PPV） hole-only devices. In this paper, we demonstrate that the current-voltage characteristics can give a good unified description of the temperature, carrier density mad electric field dependence of mobility based on both the Arrhenius temperature dependence and the non-Arrhenius temperature dependence. Fu^hermore, we perform a systematic study of charge transport and electrical properties for MEH-PPV. It is shown that the boundary carrier density has an important effect on the current-voltage characteristics. Too large or too small values of boundary carrier density will lead to incorrect cur- rent-voltage characteristics. The numerically calculated carrier density is a decreasing function of the distance to the interface, and the numerically calculated electric field is an increasing function of the distance. Both the maximum of carrier density and the minimum of electric field appear near the interface.展开更多
基金the 111 project(B12026)the National Natural Science Foundation of China(61904142)the Natural Science Basic Research Plan in Shaanxi Province of China(2019ZDLGY16-03)。
文摘This study used density functional theory and the quantum transport method to investigate the interfacial coupling and spin transport of transition metals(TMs)with a Fe,Co,and Ni/2H-VSe_(2)hybrid nanostructure.Because the indirect coupling of TM-Se-V led to an obvious reduction of the magnetic moment and the disappearance of the half-metal characteristics of 2H-VSe_(2),the expected spin-filtering effect of individual TMs and 2H-VSe_(2)deteriorated at the contact region.Nevertheless,all the TM/2H-VSe_(2)-based dual-probe devices exhibited an interesting bias-dependent spin-injection efficiency with a maximum output spin-polarized current of 666 mA mm-1 in Co/2H-VSe_(2).The proposed TM/2H-VSe_(2)-based spin-field-effect transistor demonstrated outstanding performance.The Ni/2H-VSe_(2)-based transistor achieved a maximum output spin-polarized current of 3117 m A mm-1 and demonstrated a good switching characteristic of 106 mV dec-1.Importantly,all transistors achieved a widely tunable scale of spin-extraction efficiency ranging consistently between 96%and-92%with gate bias.These results indicate a promising candidate for use in high-performance spintronic devices.
基金supported by the National Basic Research Program of China (Grant No.2007CB310407)Foundation for Innovative Research Groups of the NSFC (Grant No.61021061)+1 种基金the National Natural Science Foundation of China (Grant Nos.50972023 and 61071028)the International S&T Cooperation Program of China (Grant No.2006DFA53410)
文摘The conventional charge transport models based on density- and field-dependent mobility, only having a non-Arrhenius tem- perature dependence, cannot give good current-voltage characteristics of poly （2-methoxy-5-（2＇-ethylhexyloxy）-p-phenylene vinylene） （MEH-PPV） hole-only devices. In this paper, we demonstrate that the current-voltage characteristics can give a good unified description of the temperature, carrier density mad electric field dependence of mobility based on both the Arrhenius temperature dependence and the non-Arrhenius temperature dependence. Fu^hermore, we perform a systematic study of charge transport and electrical properties for MEH-PPV. It is shown that the boundary carrier density has an important effect on the current-voltage characteristics. Too large or too small values of boundary carrier density will lead to incorrect cur- rent-voltage characteristics. The numerically calculated carrier density is a decreasing function of the distance to the interface, and the numerically calculated electric field is an increasing function of the distance. Both the maximum of carrier density and the minimum of electric field appear near the interface.
