Re-Examination of the Size-Dependent Absorption Properties of CdSe Quantum Dots

We investigate the size-dependent optical absorption coe cients of CdSe nanocrystals at both the band-edge and high within the absorption pro le. The absorption properties in both of these regions must be self-consistent to ensure accuracy of the measured coe cients. By combining transmission electron microscopy and inductively coupled plasma - optical emission spectroscopy we map out the optical absorption properties and establish reliable size-dependent band-edge calibration curves. The measured absorption properties are compared to a simple 0D con nement model, to classical theory based on light absorption by small particles in a dielectric medium and to state-of-the-art atomistic semi-empirical pseudopotential modelling. The applicability of these newly established calibration curves is demonstrated by analyzing the nucleation and growth kinetics of CdSe nanocrystals in solution.