Silicon Clusters

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by

Charles Ufomadu



ABSTRACT

We present a review of investigation of the optical properties of passivated silicon clusters in the presence of Water. Density Functional Theory (DFT), Quantum Monte Carlo (QMC) and Ab initio calculations are employed to determine the effect of surface passivants on the optical gap of silicon nanoclusters. This study shows that the optical properties   of Si QD’s differs between solvated and unsolvated states .Since this is only a computational studies, it provides a better theoretical basis to design better Si QD which can be used as optical tags for biological sensing

INTRODUCTION
Over the last decade, the field of research surrounding molecular sensors has grown enormously. It has extended from an understanding of the optical properties of fluorescent organic molecules as optical tags through the development of Semiconductor quantum dots (QDS) such as Cadmium Selenide (CdSe) etc., up to the discovery of quantum dots made of silicon (Si). The fluorescent organic molecules are considered deficient as optical tags because their excitation requires a specific wavelength, different structures are required for a range of emission wavelength and photo bleaching readily occurs due to the decomposition   of the C-C bonds.

[Fig.1. showing an organic molecule FITC and a diagrammatic                             representation of photo bleaching over... [continues]

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