Victoria Outfield Barrier Structure In A Conductance Calculations

In this thesis, we investigated the resonance transmission of the GaAs/Ga0.5Al0.5As superlattice without/with external electric fields, and the effect of superlattice parameters on the unit area conductance.In chapter1, we introduced the research of the semiconductor superlattice electronic states, the superlattice in the electric field, the physical device of the superlattices or quantum wells and the recent developments.In chapter2,we introduced the Multi-barrier structure model, theoretical calculation of the transmission coefficient without/with electric fields, and the unit area conductance.In chapter3, we investigated the effect of GaAs/Ga0.5Al0.5As superlattice parameters on the transmission coefficient under zero and nonzero electric fields. Resonance energy in the transmission coefficient vs the incident electron energy curve corresponds to the quasi-bound energy levels in the quantum well, at the same time, the resonance energy spacing equal to the spacing of the quasi-bound energy levels spacing. We studied the relationship between the resonance transmission coefficient and the effective mass, the barrier width, the number of barriers, the effect of the biased voltage on the quasi-bound energy levels.In chapter4, we showed calculation and analysis of the relationship between the unit area conductance and the applied bias at Tâ†'0K and T> OK. We found that the temperature has no influence on the characteristic curve of the conductance with the bias voltage, but the conductance increases with increasing temperature. For the fixed width of potential well, as the barrier width increases, the spacing between the peak bias decreases, and the conductance decreases with increasing the barrier width.Chapter5is the summary of the thesis and the prospect.