Abstract
This paper analyzed single AlGaAs/GaAa heterojunction energy band structures by solving Schr dinger's equation and Poisson's equation self-consistently. Four different concentrations, positively ionized donors, holes in the valence band, free electrons in the conduction band and 2DEG are taken into account for the whole system. 2DEG from both of the structures are obtained and compared with the date available in the literatures. Differential capacitances are also calculated from the concentration profiles obtained to prove the validity of the single AlGaAs/GaAs system. Finally, theoretical predictions for both of 2DEGs and the capacitances show good agreement with the experimental data referred in this study. It has only an error of les than 10 percent.