Electronic excitations and longitudinal optical phonon modes of self-assembled CdSe quantum dots revealed by microprobe studies

The electronic states of self-assembled CdSe quantum dots and the longitudinal optical phonon mediated energy relaxation among these states are investigated. Measurements with microprobe resolution demonstrate that each quantum dot develops specific phonon modes. There is no evidence for a well-defined phonon bottleneck in the intra-quantum-dot relaxation. We observe single quantum-dot bi-exciton emission and bi-exciton binding energies exceeding 20 meV.