This paper reports the intrinsic-structure DC characteristics computed from the analytical electrochemical current theory of the bipolar field-effect transistor （BiFET） with two identical MOS gates on nanometer-thic...This paper reports the intrinsic-structure DC characteristics computed from the analytical electrochemical current theory of the bipolar field-effect transistor （BiFET） with two identical MOS gates on nanometer-thick pure-base of silicon with no generation-recombination-trapping. Numerical solutions are rapidly obtained for the three potential variables,electrostatic and electron and hole electrochemical potentials,to give the electron and hole surface and volume channel currents,using our cross-link two-route or zig-zag one-route recursive iteration algorithms. Boundary conditions on the three potentials dominantly affect the intrinsic-structure DC characteristics,illustrated by examples covering 20-decades of current （10-22 to 10-2 A/Square at 400cm^2/（V · s） mobility for 1.5nm gate-oxide, and 30nm-thick pure-base）. Aside from the domination of carrier space-charge-limited drift current in the strong surface channels,observed in the theory is also the classical drift current saturation due to physical pinch-off of an impure-base volume channel depicted by the 1952 Shockley junction-gate field-effect transistor theory,and its extension to complete cut-off of the pure-base volume channel,due to vanishing carrier screening by the few electron and hole carriers in the pure-base,with Debye length （25mm） much larger than device dimension （25nm）.展开更多
The EPR 9 factors for cubic, tetragonal and orthorhombic Fe^＋ centers in alkali halides MX （M= Li, Na; X = F, CI） are calculated from second-order perturbation formulas of g factors based on cluster approach for 3...The EPR 9 factors for cubic, tetragonal and orthorhombic Fe^＋ centers in alkali halides MX （M= Li, Na; X = F, CI） are calculated from second-order perturbation formulas of g factors based on cluster approach for 3d^7 ions in three symmetries. From calculations, the g factors of these Fe^＋ centers in MX crystals are reasonably explained and the defect structural data for the tetragonal and orthorhombic Fe^＋ centers are estimated. The results are discussed.展开更多
Traditional ligand-field theory has to be improved by taking into account both pure electronic contribution and electron-phonon interaction one （including lattice-vibrational relaxation energy）. By means of improved...Traditional ligand-field theory has to be improved by taking into account both pure electronic contribution and electron-phonon interaction one （including lattice-vibrational relaxation energy）. By means of improved ligand-field theory, the R-line, t^3 2^2 T1 lines, t^2 2（^3 T1）e^4 T2, and t^2 2（^3T1）e^4T1 bands, ground-state g factor, four strain-induced level- splittings, and R-line thermal shift of MgO：Cr^3＋ have been calculated. The results are in very good agreement with the experimental data. It is found that for MgO：Cr^3＋, the contributions due to electron-phonon interaction （EPI） come from the first-order term. In thermal shift of R-line of MgO：Cr^3＋, the temperature-dependent contribution due to EPI is dominant.展开更多
Employing variational method of Pekar type(VMPT), this paper investigates the first-excited state energy(FESE), excitation energy and transition frequency of the strongly-coupled polaron in the Cs I quantum pseudodot(...Employing variational method of Pekar type(VMPT), this paper investigates the first-excited state energy(FESE), excitation energy and transition frequency of the strongly-coupled polaron in the Cs I quantum pseudodot(QPD)with electric field. The temperature effects on the strong-coupling polaron in electric field are calculated by using the quantum statistical theory(QST). The results from the present investigation show that the FESE, excitation energy and transition frequency increase(decrease) firstly and then at lower(higher) temperature regions. They are decreasing functions of the electric field strength.展开更多
A phenomenological thermodynamic theory is applied to investigate the effect of misfit strgin and electric field on the electrocaloric effect of P（VDF-TrFN）/SrTiO3 bilayer thin films. Theoretical results indicate th...A phenomenological thermodynamic theory is applied to investigate the effect of misfit strgin and electric field on the electrocaloric effect of P（VDF-TrFN）/SrTiO3 bilayer thin films. Theoretical results indicate that the low electric field results in the decrease of the average polarization with the increase of the relative thickness of SrTi03 layer, and the high electric field has an opposite effect on it. Moreover, the electroealoric effect strongly depends on the electric field. The low electric field and the small field change can lead to a maximum of the electrocaloric effect, meanwhile the high electric field or the large field change results in the opposite trend.展开更多
文摘This paper reports the intrinsic-structure DC characteristics computed from the analytical electrochemical current theory of the bipolar field-effect transistor （BiFET） with two identical MOS gates on nanometer-thick pure-base of silicon with no generation-recombination-trapping. Numerical solutions are rapidly obtained for the three potential variables,electrostatic and electron and hole electrochemical potentials,to give the electron and hole surface and volume channel currents,using our cross-link two-route or zig-zag one-route recursive iteration algorithms. Boundary conditions on the three potentials dominantly affect the intrinsic-structure DC characteristics,illustrated by examples covering 20-decades of current （10-22 to 10-2 A/Square at 400cm^2/（V · s） mobility for 1.5nm gate-oxide, and 30nm-thick pure-base）. Aside from the domination of carrier space-charge-limited drift current in the strong surface channels,observed in the theory is also the classical drift current saturation due to physical pinch-off of an impure-base volume channel depicted by the 1952 Shockley junction-gate field-effect transistor theory,and its extension to complete cut-off of the pure-base volume channel,due to vanishing carrier screening by the few electron and hole carriers in the pure-base,with Debye length （25mm） much larger than device dimension （25nm）.
基金The project supported by National Natural Science Foundation of China under Grant No. 10274054
文摘The EPR 9 factors for cubic, tetragonal and orthorhombic Fe^＋ centers in alkali halides MX （M= Li, Na; X = F, CI） are calculated from second-order perturbation formulas of g factors based on cluster approach for 3d^7 ions in three symmetries. From calculations, the g factors of these Fe^＋ centers in MX crystals are reasonably explained and the defect structural data for the tetragonal and orthorhombic Fe^＋ centers are estimated. The results are discussed.
文摘Traditional ligand-field theory has to be improved by taking into account both pure electronic contribution and electron-phonon interaction one （including lattice-vibrational relaxation energy）. By means of improved ligand-field theory, the R-line, t^3 2^2 T1 lines, t^2 2（^3 T1）e^4 T2, and t^2 2（^3T1）e^4T1 bands, ground-state g factor, four strain-induced level- splittings, and R-line thermal shift of MgO：Cr^3＋ have been calculated. The results are in very good agreement with the experimental data. It is found that for MgO：Cr^3＋, the contributions due to electron-phonon interaction （EPI） come from the first-order term. In thermal shift of R-line of MgO：Cr^3＋, the temperature-dependent contribution due to EPI is dominant.
基金Supported by the National Natural Science Foundation of China under Grant No.11464033
文摘Employing variational method of Pekar type(VMPT), this paper investigates the first-excited state energy(FESE), excitation energy and transition frequency of the strongly-coupled polaron in the Cs I quantum pseudodot(QPD)with electric field. The temperature effects on the strong-coupling polaron in electric field are calculated by using the quantum statistical theory(QST). The results from the present investigation show that the FESE, excitation energy and transition frequency increase(decrease) firstly and then at lower(higher) temperature regions. They are decreasing functions of the electric field strength.
基金Supported by the National Natural Science Foundation of China under Grant No. 10904053Sponsored by the Priority Academic Program Development of Jiangsu Higher Education Institutions and Qing Lan Project
文摘A phenomenological thermodynamic theory is applied to investigate the effect of misfit strgin and electric field on the electrocaloric effect of P（VDF-TrFN）/SrTiO3 bilayer thin films. Theoretical results indicate that the low electric field results in the decrease of the average polarization with the increase of the relative thickness of SrTi03 layer, and the high electric field has an opposite effect on it. Moreover, the electroealoric effect strongly depends on the electric field. The low electric field and the small field change can lead to a maximum of the electrocaloric effect, meanwhile the high electric field or the large field change results in the opposite trend.
