New Theoretical Treatment of Electroreflectance from Surfaces and Interfaces Having Large Built-in Fields

Abstract

We have constructed a completely quantum-mechanical theoretical treatment of the modification of the local dielectric function by intense electric fields.It includes the numerical calculation of depletion-region bound-state energies and wavefunctions as well as band wavefunctions. We use this treatment to construct electroreflectance (ER) lineshapes.Our numerical results differ significantly from those of previously proposed ER lineshapes for GaAs with Nd >> 101.They yield excellent fits to ER data and allow the accurate determination of doping levels and band bendings from ER data.