Electric field dependence of the excitonic properties in graded double quantum wells

A quasi-bound state approximation is used to obtain the electric field depe ndence of the eigenvalues, eigenfunctions, electron-hole overlap integrals and excitonic binding energies for coupled, graded double quantum wells (GD QWs). In GDQWs the intra- and interband transitions have a much stronger el ectric held dependence than those in the square quantum well structures. Al so, unlike the single or double square wells the operation wavelength of GD QW devices can be tuned by changing not only the magnitude but also the pol arity of the applied voltage. Thus GDQWs have potential for applications in optoelectronic devices such as tunable electro-absorption modulators and i nfrared photodetectors.