Optical transitions in charged CdSe quantum dots

Using a many-body approach based on single-particle pseudopotential wave fu nctions, we calculate the dependence of the optical transitions in CdSe nan ocrystals on the presence of "spectator" electrons or holes. We find that ( i) as a result of the different localization of the electron and hole wave functions, the absorption lines shift by as much as 22 meV/unit charge when electrons or holes are loaded into the quantum dot. (ii) The lowest emissi on line is significantly red shifted with respect to the lowest allowed abs orption line. (iii) Trapping of;a "spectator" hole in a surface state is pr edicted to lead to dramatic changes in the absorption spectrum, including t he appearance of new transitions.