Combined plasmonic and dielectric rear reflectors for enhanced photocurrent in solar cells

A doubling of the photocurrent due to light trapping is demonstrated by the combination of silver nanoparticles with a highly reflective back scatterer fabricated by Snow Globe Coating on the rear of a 2 mu m polycrystalline silicon thin film solar cell. The binder free high refractive index titania particles can overcome light losses due to transmission. Modelling indicates that adding plasmonic nanoparticles to the back scatterer widens the angular distribution of scattered light such that over 80% of long wavelength light is scattered outside the Si/air loss cone and trapped in the cell, compared to 30% for the titania alone. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4729290]