Size-dependent energy levels of CdTe quantum dots

Successful observation of persistent spectral hole burning in CdTe quantum dots embedded in the glass enabled us to investigate their size-dependent electronic energy levels. Luminescence excitation spectroscopy was utilized to confirm them. The observed size-dependent electronic transitions show a monotonic increase with decrease of the radius from 4.3 to 2.5 nm and valence level crossing was not observed up to the sixth transition. These experimental results are discussed with reference to the calculated results on the multi-valence-band envelope formalism.