In this paper we present the realization of extremely thin absorber (ETA) solar cells employing conductive glass substrates functionalized with TiO 2 microstructures produced by embossing. Nanocrystalline or compact TiO 2 films on Indium doped tin oxide (ITO) glass substrates were embossed by pressing a silicon stamp containing a μm size raised grid structure into the TiO 2 by use of a hydraulic press (1 ton/50 cm 2). The performance of these microstructured substrates in a ETA cell sensitized by a thermally evaporated or chemical bath deposited PbS film and completed by a PEDOT:PSS hole conductor layer and a Au counter electrode is compared to that of planar substrates. Surprisingly planar films produced better performance than micro-structured films. A simple model implying photoconductive shunting paths revealed by junction breakdown at negative bias under illumination is presented.