Si Nanoparticles embedded in solid matrices for solar energy conversion: electronic and optical properties from first principle calculations

In device applications for solar energy conversion, nanoparticles are often embedded in a solid matrix, either crystalline or amorphous. At present a detailed understanding of the influence exerted by the embedding matrix on absorption of sunlight by the nanoparticle, and the role of the nanoparticle-matrix interface remains elusive. Building on a previous study of Si nanoparticles embedded in SiO2 [1], we investigate Si nanoparticles embedded in ZnS, used in recent experiments as a charge transport layer. A realistic model of the nanoparticle-matrix interface is created by performing ab-initio molecular dynamics simulations, and electronic and optical properties of the embedded Si nanocrystals, are obtained by first principles.\\[4pt] [1] T.Li, F.Gygi, G.Galli, Phys, Rev. Lett. 107, 206805 (2011)