Silicon nanoparticles embedded in a zinc sulfide matrix are a promising material for new types of solar cell. Computational modeling 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.
The image shows a silicon nanoparticle (grey rods), coated in sulfur atoms (yellow spheres) from the surrounding matrix. The blue blobs represent electron orbitals. This model was produced by ab initio molecular dynamics modeling 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 sulfur matrix will allow efficient separation of charges.
Coauthors on the paper are Márton Vörös, UC Davis and Adam Gali, Budapest University of Technology and Economics and Hungarian Academy of Sciences.