Stark effect studied in -doped GaAs structures

Abstract

We present a theoretical study of the subband structure of both single and periodically -doped GaAs layers. We will discuss the influence of the -doping concentration and the -layer spacing on the confinement properties of such structures. A self-consistent analysis is made on these -doping systems in two different cases: (i) in the presence of a uniform electric field and inside an infinite potential barrier and (ii) under a linearly varying built-in electric field and within a finite potential barrier. Two features have been observed for the Stark effect in the first case: (i) when the electric field increases, the energies of the electronic subbands become lower and simultaneously a second quantum well appears and (ii) for larger electric fields, the subband structure is dramatically changed and the main role of confining charge carriers is reversed to the new quantum well. In the second case, the Stark effect is studied by taking, as a finite barrier, the Schottky potential of a -GaAs diode. One main effect was observed: the distortion of the V-shaped potential being more or less accentuated, depending on the applied bias voltage being reverse or direct respectively. Photocurrent (PC) data of a Si -doped GaAs structure have been taken as experimental support to validate our computation.