Heat treatable coated article having antireflective coating(s) on substrate

A coated article including first and second antireflective (AR) coatings supported by a glass substrate, wherein the first and second AR coatings are provided on opposite sides of the glass substrate and each comprise, moving away from the glass substrate:

• a dielectric first high index layer;
• a dielectric first low index layer;
• a dielectric second high index layer;
• a dielectric second low index layer comprising an oxide of silicon;
• a dielectric third high index layer comprising an oxide of niobium;
• a dielectric first medium index layer, wherein the third high index layer comprising the oxide of niobium is located between and directly contacting the second low index layer comprising the oxide of silicon and the first medium index layer;
• a dielectric third low index layer;
• and
• an overcoat layer;
• wherein the first AR coating contains no IR reflecting layer based on silver and/or gold;
• wherein, from the perspective of a viewer of the coated article, the first and second AR coatings are configured so that the coated article has a film side reflective ΔE* value of no greater than 3.0 upon heat treatment of at least about 580 degrees C.

A method of making a coated article, the method comprising:

• heat treating a coated article at a temperature of at least 580 degrees C.,
• wherein the coated article includes a first antireflective (AR) coating supported by a glass substrate, wherein the first AR coating comprises, moving away from the glass substrate:
• a dielectric first high index layer;
• a dielectric first low index layer;
• a dielectric second high index layer;
• a dielectric second low index layer;
• a dielectric third high index layer;
• a dielectric first medium index layer, wherein the third high index layer is located between and directly contacting the second low index layer and the first medium index layer,
• wherein the dielectric first high index layer comprises a different material than that of the dielectric second high index layer, and
• wherein, from the perspective of a viewer of the coated article, the first AR coating is configured so that the coated article has a film side reflective ΔE* value of no greater than 3.0 upon the heat treating.