Separate electron-hole confinement in composite InAsyP 1-y/Ga xIn1-xAs quantum wells

Composite double qunatum wells made from materials with a type-II band line-up have been grown to realize separate confinement in real space for electrons and holes. We have observed a substantial blue shift of the lowest energy transition in such composite double quantum wells. The photocurrent measurements demonstrate a linear Stark shift due to the separate confinement in real space for electrons and holes. The charge separation is up to 45 Å in the strain balanced InAs0.42P0.58/Ga0.67In0.33As samples. The experimental results agree very well with calculations in the framework of Bir-Pikus strain Hamiltonian