First Principles and Thermodynamic Modeling of CdS Surfaces and Nanorods

Following recent reports of the successful low-temperature synthesis of high quality and single-crystal CdS quantum nanostructures, attention has turned toward identifying the critical factors affecting the preferred shape and surface structure of these important nanomaterials. Presented here are the results of first principles calculations, examining the surface structure, surface energy, and isotropic surface stress of clean reconstructed CdS low index surfaces. These results have been used as input for a shape-dependent thermodynamic model to determine the equilibrium shapes and aspect ratio of CdS nanostructures over a range of experimentally relevant sizes. The predicted shape is also directly compared with experimental results for CdS nanorods prepared using hydrothermal synthesis methods.