Nanoparticle scattering for multi-junction solar cells: the trade-off between absorption enhancement and transmission loss

Abstract

This paper contains a combined experimental and simulation study of the effect of Al and AlInP nanoparticles on the performance of multi-junction solar cells. In particular, we investigate oblique photon scattering by the nanoparticle arrays as a means of improving thinned subcells or those with low diffusion lengths, either inherently or due to radiation damage. Experimental results show the feasibility of integrating nanoparticle arrays into the ARCs of commercial InGaP/InGaAs/Ge solar cells, and computational results show that nanoparticle arrays can improve the internal quantum efficiency via optical path length enhancement. However, a design that improves the external quantum efficiency of a stateof-the-art cell has not been found, despite the large parameter space studied. We show a clear trade-off between oblique scattering and transmission loss, and present design principles and insights into how improvements can be made.