Ab-initio studies of functionalized semiconductor quantum dots

Abstract

The paper describes using first principles electronic structure calculations based on state-of-the-art time-dependent density functional theory (TDDFT), some of the optical and structural properties of semiconductor nanocrystals (quantum dots), with interest focused on understanding how these properties are influenced by functionalization of the basic nanocrystals with different types of capping molecules. The paper reports here early results obtained for small nanocrystals of silicon, illustrating on the one hand the functioning of our methodology, and on the other demonstrating the important point that the surface termination affects - in particular - the quantum dot optical properties, by comparing the optical spectra in the small size limit where the Si core of the nanocrystal consists of a single Si atom, with either H, OH, or a mixture, terminating the structure.