Measurement of the size dependent hole spectrum in CdSe quantum dots

We combine a new synthesis with transient optical hole burning to observe and assign the size evolution (19 to 115 Å diameter, σ<5%) of a series of excited states in CdSe quantum dots. We observe an avoided crossing around the spin orbit energy in the hole spectra for ∼65 Å dots, indicating the importance of valence band complexities in the description of the excited states. Comparsion with dc Stark data shows that bleach spectra are consistent with localized carrier induced electric fields.