SnO2 Transparent Printing Pastes from Powders for Photon Conversion in SnO2 -Based Dye-Sensitized Solar Cells.

Tin oxide (SnO2 ) is the most attractive alternative to titanium oxide (TiO2 ) with the aim of identifying a more positive conduction band material for dye-sensitized solar cells (DSCs). This study puts forward a protocol based on grinding, sonication, and centrifuge to generate transparent SnO2 pastes to minimize light reflectance losses from the metal oxide. Under optimized conditions, a highly transparent film with substantially enhanced light penetration depth through active layer SnO2 is realized for efficient light harvesting from two different commercially available powders (18 and 35 nm nanoparticle sizes). A ruthenium sensitizer (B11) and two organic sensitizers (NL3 and MK2) are shown to achieve higher or comparable photocurrent densities with SnO2 relative to standard TiO2 -based DSCs. SnO2 -based DSCs show minimum recombination losses, comparable charge collection efficiencies, and minimal photovoltage losses relative to TiO2 DSCs. Thus, the option of a transparent metal oxide, which can facilitate high photocurrents (>16 mA cm-2 observed) and lower recombination rates than TiO2 is an attractive material for DSC applications.