Dye-sensitized solar cells made of TiO2 are extensively studied as a cheap alternative to conventional photovoltaic cells. The other familiar stable oxide material of similar band gap suitable for dye sensitization is SnO2. Although cells based only of SnO2 are prone to severe recombination losses, the cells made of SnO2/MgO films where the SnO2 crystallite is surface covered with an ultra-thin shell of MgO, deliver reasonably high efficiencies. It is found that SnO2/MgO cells resist dye and electrolyte degradation better than TiO2 cells. Furthermore, the ultra-thin barrier of MgO on SnO2 remains intact during prolonged usage or storage of the cell. (c) 2006 Elsevier B.V. All rights reserved.