Durable silver mirror with ultra-violet thru far infra-red reflection
AssigneeThe Regents of the University of California
InventorJesse Wolfe
Life of this patent
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Abstract
A durable highly reflective silver mirror characterized by high reflectance in a broad spectral range of about 300 nm in the UV to the far infrared (˜10000 nm), as well as exceptional environmental durability. A high absorptivity metal underlayer is used which prevents the formation of a galvanic cell with a silver layer while increasing the reflectance of the silver layer. Environmentally durable overcoat layers are provided to enhance mechanical and chemical durability and protect the silver layer from corrosion and tarnishing, for use in a wide variety of surroundings or climates, including harsh or extreme environments.
Claims23
A reflective mirror having high reflectance over a large spectral range, comprising:
- a substrate comprising an absorbent metal layer on at least a surface thereof, said absorbent metal layer comprising at least one of tungsten, tantalum, nickel, chromium, and alloys thereof;
- an adhesion layer deposited on the absorbent metal layer, said adhesion layer comprising a material selected from the group consisting of nickel, nickel nitride, chromium, chromium nitride, nickel-chromium alloys, and nickel-chromium nitride;
- a reflective silver layer deposited on the adhesion layer so that light transmitted through the silver layer is absorbed by the absorbent metal layer to increase the reflection of the silver layer at all wavelengths;
- a passivation layer deposited on the silver layer, comprising a material selected from the group consisting of nickel, nickel nitride, chromium, chromium nitride, nickel-chromium alloys, and nickel-chromium nitride;
- a metal nitride layer deposited on the passivation layer;
- and
- a plurality stack of metal oxide layers deposited on the metal nitride layer.
A method for forming a reflective mirror having high reflectance over a large spectral range, comprising:
- providing a substrate comprising an absorbent metal layer on at least a surface thereof, said absorbent metal layer comprising at least one of tungsten, tantalum, nickel, chromium, and alloys thereof;
- forming an adhesion layer on the absorbent metal layer, said adhesion layer comprising a material selected from the group consisting of nickel, nickel nitride, chromium, chromium nitride, nickel-chromium alloys, and nickel-chromium nitride;
- forming a reflective silver layer on the adhesion layer so that light transmitted through the silver layer is absorbed by the absorbent metal layer to increase the reflection of the silver layer at all wavelengths;
- and;
- forming a passivation layer on the silver layer, comprising a material selected from the group consisting of nickel, nickel nitride, chromium, chromium nitride, nickel-chromium alloys, and nickel-chromium nitride;
- forming a metal nitride layer on the passivation layer;
- and
- forming a plurality stack of metal oxide layers on the metal nitride layer.
A reflective mirror having high reflectance over a large spectral range, comprising:
- a substrate;
- a reflective coating deposited on the substrate;
- a metal nitride layer;
- and
- a plurality stack of metal oxide layers deposited on the metal nitride layer, said plurality stack of metal oxide layers including:
- a first metal oxide layer selected from the group consisting of SiO2 and Al2O3 deposited on the metal nitride layer, a TiO2 layer deposited on the first metal oxide layer;
- and a plurality of split layers deposited on the TiO2 layer, each split layer selected from the group consisting of (SiO2/TaOx) SiO2 and (Al2O3/TaOx) Al2O3.
Dependencies are inferred from the claim text.