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.