Anisotropic Exchange Interaction between p-Shell Electron and s-Shell Hole in CdTe/ZnTe Quantum Dots

We study electron-hole exchange interaction in a single CdTe/ZnTe quantum dot by polarization-resolved photoluminescence measurements. We focus on recombination of excitonic states involving p-shell electrons: $X^{2-}$ and $XX^-$. Recombination lines of $X^{2-}$ and $XX^-$ states exhibit fine structure, which can be consistently explained within a model with four parameters $δ_{i}^{αβ}$ representing strength of iso- and anisotropic parts of interaction between s-hole and s- or p-electron.