Organic-acid texturing of transparent electrodes toward broadband light trapping in thin-film solar cells

An organic acid for the surface texturing of transparent electrodes is introduced, as an alternative to the conventional HCl, for efficient light trapping in thin-film solar cells. The texturing behavior of ZnO:Al by oxalic acid is investigated in terms of vertical roughness and lateral correlation length, and a mass-transport model is developed to explain the etching evolution mechanisms. Enhanced light scattering by ~8% with maintaining the sheet resistance and transparency is demonstrated, and explained by utilizing the light-scattering haze model with the extracted two surface parameters.224