Electronic structure of self-assembled InAs quantum dots in InP: An anisotropic quantum-dot system

The electronic structure of self-assembled InAs quantum dots embedded in an InP matrix has been investigated using Fourier-transform infrared spectros copy and capacitance spectroscopy. We observe a splitting of about 25 meV b etween the conduction-band excited states. We argue that this is likely to be a consequence of a strong anisotropy in the lateral size of the dots. Fu rthermore, we observe a replica in the absorption spectrum, shifted by abou t 160 meV from the fundamental, which Eve attribute to an excited heavy-hol e state. The InAs/InP dots can be well described in a simple adiabatic appr oach with a hard quantum well-like potential for the vertical confinement a nd a soft anisotropic harmonic potential for the lateral confinement. [S016 3-1829(99)50636-X].