Abstract: A large area photovoltaic device having a transparent front contact is made more efficient by a current collector grid formed over the transparent front contact to decrease the series resistance of the device. Where the front contact is between a transparent substrate and the semiconductor layers of the photovoltaic device, the collector grid is embedded in the semiconductor layers. To prevent leakage of current into the collector grid from one semiconductor layer, the collector grid material is selected to form a Schottky barrier junction with that semiconductor layer that blocks the flow of the leakage current. The process for preparing such thin film photovoltaic devices includes etching channels in the semiconductor layers, depositing the collector grid material in the channels, insulating the grid, and depositing a back electrical contact film.