Correlated development of a (2 × 2) reconstruction and a charge accumulation layer on the InAs(111)-Bi surface

We have studied the formation of a Bi-induced (2 × 2) reconstruction on the InAs(111)B surface. In connection to the development of the (2 × 2) reconstruction, a two dimensional charge accumulation layer located at the bottom of the InAs conduction band appears as seen through a photoemission structure at the Fermi level. Not well ordered Bi layers do not induce a charge accumulation. The Bi-induced reconstruction reduces the polarization of the pristine surface and changes the initial charge distribution. InAsBi alloying occurs below the surface where Bi acts as charge donor leading to the charge accumulation layer.