Effects of ZnSe and P insertion layers on band offsets at (100) GaAs/AlAs interfaces

We have theoretically investigated the effects of ZnSe and P insertion layers on the valence-band offset (ΔEv) at the (100) GaAs/AlAs interface. The theoretical calculation of ΔEv is carried out by the self-consistent sp3s∗ tight-binding method. With insertion of (ZnSe)0.5 layer, ΔEv at the (100) GaAs/AlAs interface is calculated to be 1.70 eV (increased by 1.19 eV) and −0.82 eV (reduced by 1.33 eV) on the As-terminated and the Ga-terminated GaAs, respectively, while ΔEv = 0.51 eV at the interface with no insertion layers. ΔEv is controlled by the ZnSe-induced dipole. The ZnSe insertion is promising for the artificial control of ΔEv. With insertion of a P monolayer, ΔEv is calculated to be 0.47 eV (reduced by 0.04 eV). The asymmetric GaPAl configuration at the interface changes ΔEv very slightly.