Interface phonons in spherical GaAs/${\mathrm{Al}}_{\mathit{x}}$${\mathrm{Ga}}_{1\mathrm{-}\mathit{x}}$As quantum dots

Within the framework of the dielectric continuum model, the interface phonon frequencies for spherical GaAs/${\mathrm{Al}}_{\mathit{x}}$${\mathrm{Ga}}_{1\mathrm{-}\mathit{x}}$As quantum dots are obtained as functions of the alloy composition in the range x=0.2–1.0. By imposing electrostatic boundary conditions, the two interface phonon frequencies are calculated for the first three modes. The frequency behavior of the different modes is found to be similar. However, for each mode one of the phonon frequencies is found to be strongly dependent on x. It is demonstrated that these phonon modes play an important role in determining resonant optical absorption of quantum dots.