Size and Shape Effects on Semiconductor Nanoparticles

This chapter addresses the fundamental concepts needed to understand the impact of size reduction on the electronic structure and optoelectronic properties of semiconductor nanostructures, with emphasis on quantum confinement effects. This effect is explained by two different approaches: the ``top-down'' and the ``bottom-up''. The impact of dimensionality and shape on quantum confinement is also discussed. Subsequently, a brief description of the optical properties of semiconductor nanocrystals is presented. This is followed by a discussion of the essential characteristics of nanocrystals consisting of two (or more) different semiconductors joined together by heterointerfaces (i.e., heteronanocrystals). Moreover, the essential differences between the impact of size reduction on semiconductors in comparison to metals and insulators is discussed.