On the Excitation Wavelength Dependence of the Luminescence Yield of Colloidal CdSe Quantum Dots

Abstract

Absorption and photoluminescence excitation (PLE) spectra have been recorded for colloidal CdSe quantum dots of different sizes. We find no significant deviation between the PLE and the absorption spectra, provided appropriate corrections and sample treatment are made. This implies that there is no intrinsic wavelength dependence of the luminescence quantum yield, in line with the ultrafast intraband relaxation processes reported in the literature. We suggest that a possible source for the deviations reported in the literature is the scattering produced by aggregates formed of nanodots and organic ligands in as-prepared colloidal solutions.