Dresden 2014 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 93: Frontiers of electronic structure theory - Non-equilibrium phenomena at the nano-scale VI (organized by O)

HL 93.8: Talk

Thursday, April 3, 2014, 12:30–12:45, TRE Ma

Solar nanocomposites with complementary charge extraction pathways for electrons and holes: Si embedded in ZnS — •Stefan Wippermann¹, Marton Vörös², Adam Gali³, Francois Gygi², Gergely Zimanyi², and Giulia Galli² — ¹Max-Planck-Institute for Iron Research, Düsseldorf — ²University of California, Davis — ³Budapest University of Technology and Economics

We propose that embedding silicon nanoparticles (NP) into amorphous, non-stoichiometric ZnS leads to promising nanocomposites for solar energy conversion. Using ab initio molecular dynamics simulations we show that upon high temperature amorphization of the host chalcogenide, sulfur atoms are drawn to the NP surface. We found that the sulfur content may be engineered to form a type II hetero-junction, with complementary charge transport channels for electrons and holes, and that sulfur capping is beneficial to lower the nanoparticle gap, with respect to that of NPs embedded in oxide matrices. Our analysis was conducted using density functional theory with local and hybrid functionals and many body perturbation theory at the GW level.