Correlation of texture of Ag/ZnO back reflector and photocurrent in hydrogenated nanocrystalline silicon solar cells

We studied the effect of Ag/ZnO back reflectors (BRs) with textured Ag and thin ZnO layers on hydrogenated nanocrystalline silicon (nc-Si:H) solar cell performance. We found that the photocurrent density increases with Ag texture when the surface root-mean-square (RMS) is smaller than 40 nm. The best Ag texture for nc-Si:H cells has an RMS similar to 40 nm and lateral feature size similar to 500 nm. Increasing the surface roughness further results in increased light scattering, but no additional gain in the photocurrent density is observed. Using the optimized BRs, we achieved a short circuit current density over 30 mA/cm(2) in nc-Si:H solar cells. (C) 2012 Elsevier B.V. All rights reserved.