Binding energy of charged excitons in semiconductor quantum wells in the presence of longitudinal electric fields

We present variational calculations of the binding energy for positively and negatively charged excitons (trions) in idealized ${\mathrm{G}\mathrm{a}\mathrm{A}\mathrm{s}/\mathrm{A}\mathrm{l}}_{0.3}{\mathrm{Ga}}_{0.7}\mathrm{As}$ quantum wells with parabolic electrons and holes energy dispersions. The configuration interaction method is used with a physically meaningful single-particle basis set. We have shown that the inclusion of more than one electron quantum-well solution in the basis is important to obtain accurate values for the binding energies. The effects of longitudinal electric-field and quantum-well confinement on the charged excitons bound states are studied in the absence of magnetic field and the conditions for the trion ionization are discussed.