Band discontinuity for GaAs/AlGaAs heterojunction determined by C-V profiling technique

Abstract

The band discontinuity has been determined for a GaAs/AlGaAs heterojunction prepared by molecular beam epitaxy. The conduction band‐discontinuity ΔE_c and the valence‐band discontinuity ΔE_v were independently obtained by the C‐V profiling technique, taking into account a correction for the interface charge density. The simulation was employed to confirm the reliability of the obtained band discontinuity. The ΔE_c dependence on both the Al composition of the AlGaAs layer and the heterojunction structure (AlGaAs on GaAs, or GaAs on AlGaAs) was examined. We found that ΔE_c and ΔE_v were determined to be 62 and 38% of the band‐gap discontinuity ΔE_g, being independent of the structure.