Charge carriers in organic semiconductor are different from that of traditional inorganic semiconductor. Based on three-current model, considering electrical field effect, we present a theoretical model to discuss spi...Charge carriers in organic semiconductor are different from that of traditional inorganic semiconductor. Based on three-current model, considering electrical field effect, we present a theoretical model to discuss spin-polarized injection from ferromagnetic electrode into organic semiconductor by analyzing electrochemical potential both in ferromagnetic electrode and organic semiconductors. The calculated result of this model shows effects of electrode＇s spin polarization, equilibrium value of polarons ratio, interracial conductance, bulk conductivity of materials and electrical field. It is found that we could get decent spin polarization with common ferromagnetic electrode by increasing equilibrium value of polarons ratio. We also find that large and matched bulk conductivity of organic semiconductor and electrode, small spin-dependent interracial conductance, and enough large electrical field are critical factors for increasing spin polarization.展开更多
The conductance spectra of a graphene ribbon and graphene-superconductor （G-S） junctions are investi- gated, using the tight-binding model and non-equilibrium Green＇s function formalism. It is found that the quanti...The conductance spectra of a graphene ribbon and graphene-superconductor （G-S） junctions are investi- gated, using the tight-binding model and non-equilibrium Green＇s function formalism. It is found that the quantized conductance related to graphene＇s edge-states is robust against perturbations in the model parameters for a graphene monolayer ribbon with the zigzag boundary. With appropriate a new bound state with odd-frequency symmetry is found in conductance amplitude is followed model parameter of the spin-orbit interaction strength, the G-S junction. An enhancement in the zero-energy展开更多
基金Supported by the Natural Science Foundation of Shandong Province under Grant No.Y2006A18 the Key Programme of Nature Foundation of Shandong Jianzhu University under Grant No.XZ050102
文摘Charge carriers in organic semiconductor are different from that of traditional inorganic semiconductor. Based on three-current model, considering electrical field effect, we present a theoretical model to discuss spin-polarized injection from ferromagnetic electrode into organic semiconductor by analyzing electrochemical potential both in ferromagnetic electrode and organic semiconductors. The calculated result of this model shows effects of electrode＇s spin polarization, equilibrium value of polarons ratio, interracial conductance, bulk conductivity of materials and electrical field. It is found that we could get decent spin polarization with common ferromagnetic electrode by increasing equilibrium value of polarons ratio. We also find that large and matched bulk conductivity of organic semiconductor and electrode, small spin-dependent interracial conductance, and enough large electrical field are critical factors for increasing spin polarization.
基金Supported by the National Natural Science Foundation of China under Grant No.61271163
文摘The conductance spectra of a graphene ribbon and graphene-superconductor （G-S） junctions are investi- gated, using the tight-binding model and non-equilibrium Green＇s function formalism. It is found that the quantized conductance related to graphene＇s edge-states is robust against perturbations in the model parameters for a graphene monolayer ribbon with the zigzag boundary. With appropriate a new bound state with odd-frequency symmetry is found in conductance amplitude is followed model parameter of the spin-orbit interaction strength, the G-S junction. An enhancement in the zero-energy
