Abstract
An approach toward truly monosized nanocrystals based on a mechanism of the chemical potential well during crystal growth is presented. Nanocrystals are first grown to sizes corresponding to stable cry stall ographic configurations in a lower energy state, for example, the magic closed-shell structure. Second, the nanocrystals are treated by a quenching process to suspend the crystal growth, which can place the nanocrystals in the chemical potential well generated by the stable magic closed-shell structure. The last isothermal annealing provides a thermodynamic regime for the nanocrystals to adjust their sizes and morphology to the magic closedshell structure, which finally narrows the size distribution. By this approach, size deviation of CdSe nanocrystals with 3.6 nm diameter is reduced about 45%. The final size deviation is limited by random temperature fluctuations from a heating source. © 2009 American Chemical Society.