Fully self-consistent calculation of the electronic structure ofn-type InAs accumulation layers

The screening of an external electric field at the surface of a degenerate semiconductor is modified in narrow-band-gap materials due to ``motional binding,'' where the confinement potential for surface-bound states depends on electron motion along the surface. A self-consistent calculation is presented that includes motional binding and treats both bound and mobile charge on the same footing. The calculation is applied to accumulation layers on n-type InAs and very good agreement is obtained with existing Shubnikov--de Haas data. The calculation is also used to predict intersubband spacings under conditions of motional binding.