We have investigated the flexible thin-film silicon (Si) solar cells fabricated on the flexible glass substrates. The preliminary p-i-n type flexible hydrogenated amorphous silicon (a-Si:H)/hydrogenated microcrystalline silicon (mu c-Si:H) double-junction solar cell is compared with its counterpart fabricated on the textured F-doped tin oxide-coated glass substrate. Because of the inferior light transmitting and scattering of the SnO2:F front electrode coated by a spray pyrolysis deposition in the long wavelength region, the preliminary flexible solar cell shows a severely limited short-circuit current. Without any back reflector, the initial efficiency of 8.0% and stabilized efficiency of 7.1% are achieved. The initial efficiency of 9.3% was achieved by improving the current matching. The superstrate type thin-film Si photovoltaic technology using flexible transparent substrates has a high potential to minimize the cell-to-module loss through a monolithic series integration using a laser scribe technique. (C) 2013 Elsevier B.V. All rights reserved.