Angular Momentum Fine Structure in InP/ZnSe Quantum Dots.

There is a large experimental and theoretical literature on the angular momentum fine structure of the lowest energy exciton in InP-based quantum dots. This literature is highly contradictory, and no clear picture of the fine structure accounting for all these results is available. This paper presents a quantitative analysis of recently published luminescence anisotropy results and presents an analysis of the different proposed fine structure models that compares radiative lifetimes calculated from those models with experimental values. These analyses show that the lowest energy (dark) state is the m = ±2 state and the lowest energy bright state is a vibronically allowed phonon level. The splittings between the ±2/±1 states and the ±1/0 states are the same, about 28 meV. We also find that the manifold of J = 1 states is about 60 meV above the manifold of J = 2 states.