Nano-size textured topography is important to gain high absorption ratio of the incoming light for thin film solar cells. In this paper, a Ga2O3 nano-islands coated glass substrate is introduced by annealing Ga nano-islands in air. The aspect ratio of the islands can be easily controlled by tuning the average thickness of Ga film. Based on the proposed substrate, with average horizontal size of 500 nm and root-mean-square roughness of 80 nm of the nano-islands, the average reflectivity under AM 1.5 illumination spectrum can be limited at 6.6% when Si absorber layer is only 480 nm thick. (C) 2011 Elsevier Ltd. All rights reserved.