Improved Nanophotonics Simulation Tools for Light-Trapping in Photovoltaics

S. Shepard and F. Rubaiat
Louisiana Tech University, US

Keywords: solar energy, photovoltaics, light trapping, nanoparticle scattering

Summary:

Models used in the field of nanoparticle enhanced light-trapping have a wide range of complexity. Often one simply calculates how much power is absorbed in a particular region e.g., a layer of silicon withing a photovoltaic device. It is important to distinguish however “bad” material absorptions from the “good” absorptions which generate current (within a PN junction). Supercomputer simulations can incorporate both the carrier dynamics within a PN junction as well as the optical scattering from nanoparticles but these are too complex for most purposes. We describe herein a new nanophotonic simulation methodology in which we circumvent the complexities of carrier dynamics via an efective loss based on measured responsivity data to model the PN junction. A model for incorporating responsivity in an ad hoc way is shown to yield reasonable results in a how loss limit. We go beyond that limit via another model in which we allow the power we extract from the device to influence the quality of the trap itself.