External light-trapping for solar cells using a 3D-printed parabolic concentrator array

Abstract

Reflection of light is a major efficiency loss in solar cells. Most optical absorption enhancement methods in solar cells increase surface recombination. An array of external light-traps can increase optical absorption without deteriorating cell quality. We fabricated square, hexagonal and circular parabolic light-traps for solar cells. We performed electrical and spectral response measurements on an organic photovoltaic cell, with and without 3D-printed light-traps. The external quantum efficiency of the cell shows that for almost all wavelengths of interest, the traps improve the efficiency of the solar cell. We made a 2x2 array of square traps that improves the efficiency of the cell.