Forward scattering nanoparticles based nanostructure for light trapping over solar spectrum

We present a lossless, strong forward-scattering nanostructure for high-performance light trapping over the solar spectrum. This solar harvesting configuration consists of forward-scattering nanoparticle arrays largely embraced in an appropriate medium and partially embedded in a silicon thin film. Nanoparticles or nanoparticle clusters processing better forward-scattering than other reported structures over a wide wavelength range were obtained by tuning their magnetic and electric responses via the change of either structural configurations or surrounding media or both. Results show that lossless titania (TiO₂) nanoparticles embraced in a glass medium scatter light in forward direction and with partial embedding greatly increase the light trapping in a silicon substrate of varying thicknesses. In particular, the nanostructure, consisting of 500 nm TiO₂ nanoparticles embedded 90 nm into a 200 nm thin film silicon cell, yields an increment of 10.3 mA/cm² in short-circuit current density over the bare thin film silicon cell or absorbs 3.15 times as much light as the bare one.