In this study, we investigated the effect of the multi-step texturing process on the electrical and optical properties of hydrogenated Al-doped zinc oxide (HAZO) thin films deposited by RF magnetron sputtering. After their deposition, the surface of the HAZO films was multi-step textured in dilute HCl (0.5%) to investigate the change in their optical properties and surface morphology due to etching. The HAZO film fabricated under the type III condition showed excellent optical properties with a haze value of 50.81%. The microcrystalline silicon (mu c-Si:H)-based p-i-n solar cells prepared using these new texture-etched HAZO substrates showed high quantum efficiencies in the long wavelength range, thereby demonstrating effective light trapping. Using the optimum AZO:H thin film textured surface, we achieved a p-i-n mu c-Si solar cell efficiency of 7.08%. Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved.