1 min readModelling of Silicon Nanoparticles for Solar Energy
Davis, CA – Silicon nanoparticles embedded in a zinc sulphide matrix are a promising material for new types of solar cell. Computational modelling by Stefan Wipperman, Gergely Zimanyi, Francois Gygi and Giulia Galli at UC Davis and colleagues shows how such a material might work.
“Designing materials with desired properties for renewable energy application is a topic of great current interest in physics, chemistry, and materials science, and one of the goals of the Materials Genome initiative, launched in the US in 2011. Our paper focuses on the search for design rules to predict Earth abundant materials for the efficient conversion of solar energy into electricity,” Zimanyi said in an email.
Their work is published March 14 in the journal Physics Review Letters.
The image shows a silicon nanoparticle (grey rods), coated in sulphur atoms (yellow spheres) from the surrounding matrix. The blue blobs represent electron orbitals. This model was produced by ab initio molecular dynamics modelling and electron structure calculations, Zimanyi said.
Incoming photons create electron/hole pairs. A solar cell generates current by separating negatively-charged electrons and positive holes to different electrodes. In this structure, the models predict that the junction between nanoparticle and the zinc sulphur matrix will allow efficient separation of charges.
Publication: Solar Nanocomposites with Complementary Charge Extraction Pathways for Electrons and Holes. Si Embedded in ZnS. Stefan Wippermann, Márton Vörös, Adam Gali, Francois Gygi, Gergely T. Zimanyi, and Giulia Galli. Phys. Rev. Lett. (March 2014): http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.112.106801