Patent ID: 8153282

Claim:
A photovoltaic device comprising: a photovoltaic layer and at least a glass substrate on a light incident side of the photovoltaic layer; an anti-reflection coating provided on the glass substrate, the anti-reflection coating being located on a light-incident side of the glass substrate; wherein the anti-reflection coating consists essentially of a graded layer provided directly on and contacting the glass substrate and a layer comprising silicon oxide over and contacting the graded layer, the graded layer including a mixture of silicon oxide, and titanium oxide supplemented with zirconium oxide, with more titanium oxide and zirconium oxide being provided in a far portion of the graded layer farther from the glass substrate than in a near portion of the graded layer closer to the glass substrate, and wherein the graded layer has a thickness of at least one wavelength; and wherein the layer comprising silicon oxide has about a quarter-wavelength thickness and is located on and directly contacting the graded layer.