模拟掺杂和偏压对超晶格纵向输运的影响

结合宏观和微观模型，超晶格的纵向输运模型可以表达为以时间丁为独立变量的微分方程组．运用MATLAB软件进行模拟计算和优化，深入研究掺杂浓度和外加偏压的变化，对GaAs／AlAs掺杂弱耦合超晶格自维持振荡频率和振幅的影响．结果表明，电流振荡频率随偏置电压的增加而单调减小，振幅相对偏置电压也有大体上单调的变化．随着掺杂浓度的增加，振荡频率有非单调的变化，而振幅则单调地逐渐减小．电流振荡频率随偏置电压的变化趋势与已有的实验数据基本一致，其他模拟计算结果还有待进一步实验的验证．

Simulating Effeat of Doping Density and Bias Voltage on Frequency and Amplitude of Self-Sustained Oscillation of Weakly Coupled GaAs/AlAs Supperlattice

combining macroscopic model with microscopic one, the vertical transportable model of superlattice can be expressed as differential equations taking time t as unique variable. By using MATLAB software, the authors carry out simulation computation and optimization; and study in a deep-going way the effect of the change of doping density and external bias voltage on frequency and amplitude of self-sustained oscillation of doped GaAs/AlAs superlattice with weak coupling. As shown by the results, the frequency of current oscillation monotonically reduced with the inerease of bias voltage, while the amplitude shows also more or less monotonic change in relation to bias voltage; With the increase of doping density, the frequency shows nonmonotonic change while the amplitade decreases gradually and monotonically. In which the trend that the frequency of current oscillation changes with bias voltage agrees basically with experimental data now available; other results of simulation computation remain to be tested and verified by further experiment.