Gate current for pMOSFETs is composed of direct tunneling current,channel hot hole,electron injection current,and highly energetic hot holes by secondary impact ionization.The device degradation under V g=V d/2 is m...Gate current for pMOSFETs is composed of direct tunneling current,channel hot hole,electron injection current,and highly energetic hot holes by secondary impact ionization.The device degradation under V g=V d/2 is mainly caused by the injection of hot electrons by primary impact ionization and hot holes by secondary impact ionization,and the device lifetime is assumed to be inversely proportional to the hot holes,which is able to surmount Si-SiO 2 barrier and be injected into the gate oxide.A new lifetime prediction model is proposed on the basis and validated to agree well with the experiment.展开更多
The influence of implantation of N+ions of different energies on the nanostructure of7049Al substrates and the corrosioninhibition of produced Al samples in a3.5%NaCl solution was studied.The X-ray diffraction(XRD)res...The influence of implantation of N+ions of different energies on the nanostructure of7049Al substrates and the corrosioninhibition of produced Al samples in a3.5%NaCl solution was studied.The X-ray diffraction(XRD)results confirmed the formationof AlN as a result of N+ion implantation.The atomic force microscope(AFM)results showed that grains of larger scale are formedby increasing N+energy which can be due to heat accumulation in the sample during implantation causing higher rate of diffusion inthe sample,hence decreasing the number of defects.Corrosion resistance of the samples was studied by the electrochemicalimpedance spectroscopy(EIS)measurements.Results showed that corrosion resistance of implanted Al increases with increasing N+ion energy.The equivalent circuits for the N+implanted Al samples with different energies were obtained,using the EIS data whichshowed strong dependence of the equivalent circuit elements on the surface morphology of the samples.Finally,the relationshipbetween corrosion inhibition and equivalent circuit elements was investigated.展开更多
The change of light output power of LEDs based on A1GalnP heterostructures with multiple quantum wells （590 nm and 630 nm） under irradiation by fast neutrons depends on the operating current density. It can be disti...The change of light output power of LEDs based on A1GalnP heterostructures with multiple quantum wells （590 nm and 630 nm） under irradiation by fast neutrons depends on the operating current density. It can be distinguished the regions of high, average and low electron injection. Operating current, this corresponds to the position of the boundary between the selected levels of the electron injection, increases with increasing neutron fluence. The final stage of the reducing process of the light output power under irradiation is the regime of low electron injection. The relative change in light output power depends on the operating current （operating current density） and can be described by a fairly simple equation. Established relations predict radiation resistance of LEDs, and it makes the most rational justification of operating modes of light-emitting diodes in terms of radiation resistance.展开更多
Metal halide perovskite light emitting diodes(PeLEDs)have recently experienced rapid development due to the tunable emission wavelengths,narrow emission linewidth and low material cost.To achieve stateof-the-art perfo...Metal halide perovskite light emitting diodes(PeLEDs)have recently experienced rapid development due to the tunable emission wavelengths,narrow emission linewidth and low material cost.To achieve stateof-the-art performance,the high photoluminescence quantum yield(PLQY)of the active emission layer,the balanced charge injection,and the optimized optical extraction should be considered simultaneously.Multiple chemical passivation strategies have been provided as controllable and efficient methods to improve the PLQY of the perovskite layer.However,high luminance under large injection current and high external quantum efficiency(EQE)can hardly be achieved due to Auger recombination at high carrier density.Here,we decreased the electron injection barrier by tuning the Fermi-level of the perovskite,leading to a reduced turn on voltage.Through molecular doping of the hole injection material,a more balanced hole injection was achieved.At last,a device with modified charge injection realizes high luminance and quantum efficiency simultaneously.The best device exhibits luminance of 55,000 cd m^-2 EQE of 8.02%at the working voltage of 2.65 V,current density of 115 mA cm^-2,and shows EQE T50 stability around 160 min at 100 mA cm^-2 injection current density.展开更多
A double T-shaped device model is constructed to investigate the spin polarized current injection and transportation properties in organic semiconductors.Based on the spin diffusion theory and Ohm’s law and consideri...A double T-shaped device model is constructed to investigate the spin polarized current injection and transportation properties in organic semiconductors.Based on the spin diffusion theory and Ohm’s law and considering the different charge-spin relationship of the special carriers in organic semiconductors,the current spin polarization has been obtained.Effects of the branch current ratio and the polaron proportion on the spin polarized current injection efficiency are studied.From the calculation,it is found that the improvement of the spin polarized current injection efficiency can be obtained by adjusting the branch current ratio;moreover,high polaron proportion in organic semiconductors is beneficial for obtaining high current spin polarization.展开更多
Manipulation of antiferromagnetic(AFM) spins by electrical means is on great demand to develop the AFM spintronics with low power consumption. Here we report a reversible electrical control of antiferromagnetic moment...Manipulation of antiferromagnetic(AFM) spins by electrical means is on great demand to develop the AFM spintronics with low power consumption. Here we report a reversible electrical control of antiferromagnetic moments of FeMn up to 15 nm, using an ionic liquid to exert a substantial electric-field effect. The manipulation is demonstrated by the modulation of exchange spring in[Co/Pt]/FeMn system, where AFM moments in FeMn pin the magnetization rotation of Co/Pt. By carrier injection or extraction,the magnetic anisotropy of the top layer in FeMn is modulated to influence the whole exchange spring and then passes its influence to the [Co/Pt]/FeMn interface, through a distance up to the length of exchange spring that fully screens electric field. Comparing FeMn to IrMn, despite the opposite dependence of exchange bias on gate voltages, the same correlation between carrier density and exchange spring stiffness is demonstrated. Besides the fundamental significance of modulating the spin structures in metallic AFM via all-electrical fashion, the present finding would advance the development of low-power-consumption AFM spintronics.展开更多
基金国家重点基础研究发展计划 ( No.G2 0 0 0 0 3 65 0 3 ) Motorola Digital DNA Laboratory资助项目~~
文摘Gate current for pMOSFETs is composed of direct tunneling current,channel hot hole,electron injection current,and highly energetic hot holes by secondary impact ionization.The device degradation under V g=V d/2 is mainly caused by the injection of hot electrons by primary impact ionization and hot holes by secondary impact ionization,and the device lifetime is assumed to be inversely proportional to the hot holes,which is able to surmount Si-SiO 2 barrier and be injected into the gate oxide.A new lifetime prediction model is proposed on the basis and validated to agree well with the experiment.
基金University of Tehran and the Iran National Science Foundation(INSF)center of excellence for structural and microscopic properties of matter,Department of Physics,University of Tehran for partial support of this work
文摘The influence of implantation of N+ions of different energies on the nanostructure of7049Al substrates and the corrosioninhibition of produced Al samples in a3.5%NaCl solution was studied.The X-ray diffraction(XRD)results confirmed the formationof AlN as a result of N+ion implantation.The atomic force microscope(AFM)results showed that grains of larger scale are formedby increasing N+energy which can be due to heat accumulation in the sample during implantation causing higher rate of diffusion inthe sample,hence decreasing the number of defects.Corrosion resistance of the samples was studied by the electrochemicalimpedance spectroscopy(EIS)measurements.Results showed that corrosion resistance of implanted Al increases with increasing N+ion energy.The equivalent circuits for the N+implanted Al samples with different energies were obtained,using the EIS data whichshowed strong dependence of the equivalent circuit elements on the surface morphology of the samples.Finally,the relationshipbetween corrosion inhibition and equivalent circuit elements was investigated.
文摘The change of light output power of LEDs based on A1GalnP heterostructures with multiple quantum wells （590 nm and 630 nm） under irradiation by fast neutrons depends on the operating current density. It can be distinguished the regions of high, average and low electron injection. Operating current, this corresponds to the position of the boundary between the selected levels of the electron injection, increases with increasing neutron fluence. The final stage of the reducing process of the light output power under irradiation is the regime of low electron injection. The relative change in light output power depends on the operating current （operating current density） and can be described by a fairly simple equation. Established relations predict radiation resistance of LEDs, and it makes the most rational justification of operating modes of light-emitting diodes in terms of radiation resistance.
基金in part supported by Research Grants Council of Hong Kong,particularly,via Grant Nos.Ao E/P-03/08,T23-407/13-N,Ao E/P-02/12,14207515,14204616CUHK Group Research Scheme,and ITS/088/17 by Innovation and Technology Commission,Hong Kong SAR Governmentthe National Natural Science Foundation of China for the support,particularly,via Grant No.61229401。
文摘Metal halide perovskite light emitting diodes(PeLEDs)have recently experienced rapid development due to the tunable emission wavelengths,narrow emission linewidth and low material cost.To achieve stateof-the-art performance,the high photoluminescence quantum yield(PLQY)of the active emission layer,the balanced charge injection,and the optimized optical extraction should be considered simultaneously.Multiple chemical passivation strategies have been provided as controllable and efficient methods to improve the PLQY of the perovskite layer.However,high luminance under large injection current and high external quantum efficiency(EQE)can hardly be achieved due to Auger recombination at high carrier density.Here,we decreased the electron injection barrier by tuning the Fermi-level of the perovskite,leading to a reduced turn on voltage.Through molecular doping of the hole injection material,a more balanced hole injection was achieved.At last,a device with modified charge injection realizes high luminance and quantum efficiency simultaneously.The best device exhibits luminance of 55,000 cd m^-2 EQE of 8.02%at the working voltage of 2.65 V,current density of 115 mA cm^-2,and shows EQE T50 stability around 160 min at 100 mA cm^-2 injection current density.
基金supported by the National Natural Science Foundation of China(Grant Nos.10904083 and 10904084)the Project of Shandong Provincial Higher Educational Science and Technology Program(Grant No.J13LA05)the Excellent Young Scholars Research Fund of Shandong Normal University
文摘A double T-shaped device model is constructed to investigate the spin polarized current injection and transportation properties in organic semiconductors.Based on the spin diffusion theory and Ohm’s law and considering the different charge-spin relationship of the special carriers in organic semiconductors,the current spin polarization has been obtained.Effects of the branch current ratio and the polaron proportion on the spin polarized current injection efficiency are studied.From the calculation,it is found that the improvement of the spin polarized current injection efficiency can be obtained by adjusting the branch current ratio;moreover,high polaron proportion in organic semiconductors is beneficial for obtaining high current spin polarization.
基金supported by the National Natural Science Foundation of China(Grant Nos.51322101,51231004 and 51571128)the Ministry of Science and Technology of China(Grant No.2014AA032904)
文摘Manipulation of antiferromagnetic(AFM) spins by electrical means is on great demand to develop the AFM spintronics with low power consumption. Here we report a reversible electrical control of antiferromagnetic moments of FeMn up to 15 nm, using an ionic liquid to exert a substantial electric-field effect. The manipulation is demonstrated by the modulation of exchange spring in[Co/Pt]/FeMn system, where AFM moments in FeMn pin the magnetization rotation of Co/Pt. By carrier injection or extraction,the magnetic anisotropy of the top layer in FeMn is modulated to influence the whole exchange spring and then passes its influence to the [Co/Pt]/FeMn interface, through a distance up to the length of exchange spring that fully screens electric field. Comparing FeMn to IrMn, despite the opposite dependence of exchange bias on gate voltages, the same correlation between carrier density and exchange spring stiffness is demonstrated. Besides the fundamental significance of modulating the spin structures in metallic AFM via all-electrical fashion, the present finding would advance the development of low-power-consumption AFM spintronics.
