Patent ID: 7846492

Claim:
A method of making a heat treated coated article, the method comprising: providing a coating supported by a glass substrate, the coating comprising a zirconium nitride based layer; thermally tempering the glass substrate with the zirconium nitride based layer thereon, so that the tempering causes the zirconium nitride based layer to transform into a layer comprising zirconium oxide (Zr x O y ) where y/x is from about 1.2 to 2.5; and following said tempering, forming a photocatalytic layer comprising anatase TiO 2 on the glass substrate over and directly contacting the layer comprising zirconium oxide (Zr x O y ), wherein the photocatalytic layer is initially deposited in a wet form including titania colloids in solution, wherein deposition of the photocatalytic layer in wet form causes the photocatalytic layer to have a nano-porosity sufficient to cause a refractive index of the photocatalytic layer to substantially match a refractive index of the layer comprising zirconium oxide.