Electronic states of elongated PbSe/PbS Core/shell quantum dots

The optical characteristics of colloidal quantum dots (QDs) are highly dependent on the physical geometry of the QD (size, shape) as well as composition. These dependencies make such systems attractive for application in novel optical devices, notably for solar cell technology. Empirical electronic structure methods, such as k·p theory, or empirical pseudopotential theories have successfully reproduced experimentally observed transitions in CdSe and PbSe colloidal QDs. Our approach uses the k·p method to predict such properties as the electronic structure and dipole transitions of ellipsoidal PbSe/PbS core/shell structure colloidal QDs, as a function of eccentricity. Due to the anisotropy between the longitudinal (z) and transverse (x and y) directions, we present results from elongation along both the x and z directions.