NOVELTY - Low-temperature conformal metal oxide coating (5) is formed by coating a substrate (3) with non-hydrolyzed precursor solution of moisture-sensitive metal alkoxide(s) in organic solvent at at most 150degreesC; and rinsing precursor solution coated on the surface in water at less than 150degreesC to hydrolyze precursor solution at the surface of the substrate and form a conformal metal oxide coating on the substrate.    USE - For fabricating conformal metal oxide coating on surface, such as flat, structured, nanoporous or reticulated surface, of substrate or on nanocrystalline film for device, e.g. optoelectronic device, photovoltaic device, or dye sensitized solar cell (claimed).    ADVANTAGE - The method allows for the fabrication of coatings having a thickness of less than 1 to hundreds of nanometers, with repeated deposition allowing for the fabrication of coatings of increased thickness. It reduces cost and environmental waste, and allows for the coating of temperature-sensitive substrates, particularly organic substrate such as polymers and plastics.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following:    (1) a device incorporating a substrate having a metal oxide coating;    (2) a dye sensitized solar cell device comprising nanocomposite film between pair of electrodes, where the film comprises mesoporous nanocrystalline film conformally coated with a first coating of metal oxide and a second coating of sensitizing dye, and a redox-active electrolyte interpenetrated into the pores of the film;    (3) a non-hydrolyzed precursor solution of moisture-sensitive metal alkoxides in an organic solvent; and    (4) a method of preparing a non-hydrolyzed precursor solution of moisture-sensitive metal alkoxides in an organic solvent, comprising mixing the alkoxides in the solvent in a controlled environment containing less than 100 ppm water.    DESCRIPTION OF DRAWING(S) - The figure schematically represents the fabrication steps in fabricating conformal metal oxide coating on a substrate.    Substrate (3)    Metal oxide coating (5)