dA highly efficient solid-state solar cell (TiO2/dye/CuI) with improved stability was fabricated by controlling the pore filling of the porous dyed TiO2 layer with molten salt capped CuI crystals and improving the TiO2 by necking with ZnO. The molten salt controls the CuI crystal growth and acts as a protective coating for CuI nanocrystals, and necking with the more conductive ZnO improves electrical contact between TiO2 particles, both contributing to improved cell performance. Cells achieved efficiency as high as 3.8% with improved stability under continuous illumination for about 2 weeks.