Light-trapping and antireflective coatings for amorphous Si-based thin film solar cells

In this paper, we study the efficiency of several types of all-dielectric, non-resonant, antireflection, and light-trapping coatings for the enhancement of photovoltaic absorption in thin-film silicon solar cells. We compare the enhancement of the photovoltaic absorption offered by a square array of nano-pillar shaped voids in the dielectric covering of the cell with that granted by a flat blooming layer, and a densely packed array of dielectric nanospheres. We optimize these coatings and show that the newly proposed nanostructure allows a significant increase of the photovoltaic absorption. The dependence of antireflection and light-trapping properties on the angle of incidence is numerically investigated, and it is shown that the array of voids keeps optimal also after averaging over the incidence angles. (c) 2015 AIP Publishing LLC.