用赝势微扰法计算某些半导体的能带结构(用于GaAs,GaP和Ga[As1-xPx]合金)

用赝势微扰法计算了GaAs,GaP和GaAs_1-xP_x]合金的能带。赝势选择的原则是使计算所得直接能隙和间接能隙与实验值相符合。计算结果表明,不但能带次序准确,而且与室温下的实验值符合得很好。基于由GaAs到GaP晶格常数和赝势是线性变化的假设,计算了GaP含量为20％,50％和80％时GaAs_1-xP_x]合金的能带。当GaP含量为41％时,直接能隙和间接能隙相等,这一数值刚好是Spitzer和Fenner的实验值的平均值。此时,由于很好满足光激射器p-n结所要求的条件,因此可望在光激射器中得到应用,它们的能带也就有一定的参考价值。

THE CALCULATION OF THE ENERGY-BAND STRUCTURE OF SOME SEMICONDUCTORS WITH THE PSEUDOPOTENTIAL PERTURBATION METHOD (APPLICATION TO GaAs, GaP AND Ga[As1-xPx]ALLOY)

The energy-band structures of the GaAs, GaP, and Ga As_1-xP_x] alloys have been calculated on the "empty lattice" assumption by taking the pseudopotential as perturbations.The pseudopotential parameters are chosen so as to make the calculated direct and indirect energy gap agree with that given by the experiments. The results thus obtained are in good agreement with experimental data at room temperature. Assuming that the lattice constant and pseudopotential parameters vary linearly from GaAs to GaP, we have calculated the energy band of the GaAs_1-xP_x] alloys for x=0.2, 0.5, and 0.8. The direct and indirect energy gap is equal at x=0.41 which is in reasonable agreement with the results of Spitzer and Fenner.