Shape dependent properties of CdSe nanostructures

We investigate the impact of surface character, shape and size of CdSe particles on their electrostatic and structural properties and discuss consequences for their role as sensitizers. Other than previous theoretical studies which have focussed on a fixed particle shape and a small set of sizes we systematically investigate a large set of more than a thousand nanocrystals with different shapes, sizes, and aspect ratios. This novel approach allows us to draw conclusions on significant correlations of the relevant properties of these crystals with shape, surface character and size. In particular, we find significant differences between the properties of approximately spherically shaped particles, and particles with well defined surfaces along crystal planes but also between particles of the latter class. A surprisingly strong impact of the specific shape and surface configuration is found for the internal structure well inside the crystal as measured by bond lengths correlated with coordination numbers. (C) 2009 Elsevier B.V. All rights reserved.