Simultaneous effect of impurities, hydrostatic pressure, and applied potential on the optical absorptions in a GaAs field-effect transistor

Abstract

This work theoretically investigates the impact of structural parameters on energy levels and optical absorption coefficients in an Si-delta doped GaAs field-effect transistor δ-FET. The structural parameters include the doping concentration of the planar silicon layer, the applied hydrostatic pressure P, and the contact potential VC. The energy levels and their corresponding wavefunctions were calculated using the effective mass approximation by solving the Schrödinger equation while taking into account the Hartree and exchange potentials. At higher doping concentrations and applied hydrostatic pressures, the optical absorption coefficients shifted towards higher energies (blue shift). However, when the applied voltage VC increased, we noted either red-shift or a blue-shift. This findings is a very important result of this work. Our results may be useful for designing and fabricating optoelectronic devices that, depend on hydrostatic pressure and contact voltage.