Intersubband optical absorption of double Si delta-doped GaAs layers

Abstract

For different applied electric fields the intersubband transitions of double Si delta-doped GaAs structures are theoretically investigated for a uniform donor distribution. The electronic structure has been calculated by solving the Schrodinger and Poisson equations self-consistently. It is found that the changes of the confining potential, the subband energies and intersubband optical absorption are quite sensitive to the applied electric field. Different from the single delta-doped structure, we have seen the abrupt changing of the subband energies and the absorption coefficient whenever the applied electric field reaches two certain values. While for the (1-2) intersubband transition, the intersubband absorption spectrum shows blueshifts up to the first critical electric field value, this spectrum shows redshifts up to the second critical electric field value and shows blueshifts for higher electric fields than the second critical field values. This behavior in the intersubband transitions for different electric fields can be used in some infrared optical device applications based on the intersubband transitions of electrons. (C) 2004 Elsevier Ltd. All rights reserved.