The Effect of The Geometry of Side Quantum Wells on The Optical Properties of Triple Quantum Wells Under The Electric Field Influence

The electronic and optical properties of the symmetrical 〖Al〗_x 〖Ga〗_(1-x) As/GaAs multiple quantum wells were investigated. The system consists of three triangular-shaped quantum wells in which the potentials of left- and right-hand side wells were shallower in comparison with that of the center well. The calculations were carried out for different potential shapes as the triangular shapes of the left- and right-hand side wells varied from triangle to square shape keeping the center well potential constant. The energy levels were calculated using the finite difference method under the effective mass approximation, with and without an electric field. When the geometry of the side wells was changed from shallow triangular side wells to square side wells in the absence of an electric field, the optical transitions were found to shift towards smaller photon energies. When an electric field was applied, the optical absorption and refractive index changes for the (1-2) transition exhibited interesting behavior. It was found that the electronic and optical properties of structures can be controlled by the externally applied electric field by selecting appropriate structural parameters.