Elemental semiconductor mirror for vehicles and method for making same

A spectrally selective mirror for vehicles having a rearmost surface positioned farthest from a source of incident light to be reflected by said mirror comprising:

• a substrate having front and rear surfaces;
• a thin layer of an elemental semiconductor, and a single, thin, transparent interference coating on said semiconductor thin layer;
• said elemental semiconductor thin layer coated with said interference coating providing said elemental semiconductor thin layer with an index of refraction of at least 3 and an optical thickness of at least 275 angstroms;
• said interference coating having an index of refraction within the range of between about 1.3 and 2.7, an optical thickness of at least about 500 angstroms, and being positioned closest to the source of incident light to be reflected by said mirror;
• said elemental semiconductor thin layer coated with said interference coating providing said mirror with a luminous reflectance of at least 30% of the light incident thereon from the direction of said front surface of said substrate and including a light absorbing coating on said rearmost surface of said mirror which absorbs light transmitted by said substrate and/or elemental semiconductor thin layer and interference coating.

A high luminous reflectance mirrored substrate comprising:

• a glass substrate having first and second surfaces:
• a reflector coated upon said first surface thereof, said first surface adapted to face a source of light to be reflected;
• said reflector comprising a multilayer thin film stack consisting of a first thin film layer of elemental silicon which is closest to said first surface of said glass substrate and has a refractive index of greater than 3.0, a second thin film layer which is farthest from said second surface of said glass substrate, and a third film layer disposed between said first thin film layer and said second thin film layer, said third thin film layer having a refractive index between about 1.3 and 2.7, said second thin film layer having a refractive index greater than said third thin film layer;
• and
• said reflector having a light reflectance of at least about 60% of light incident thereon at the wavelength region of about 550 nanometers and being achromatic.

A high luminous reflectance mirrored substrate comprising:

• a glass substrate having first and second surfaces:
• a reflector coated upon said second surface thereof, said second surface adapted to face away from a source of light to be reflected;
• said reflector comprising a multilayer thin film stack consisting of a first thin film layer of elemental silicon which is farthest from said second surface of said glass substrate and has a refractive index of greater than 3.0, a second thin film layer which is closest to said second surface of said glass substrate, a third thin film layer disposed between said first thin film layer and said second thin film layer, said third thin film layer having a refractive index between about 1.3 and 2.7, said second thin film layer having a refractive index greater than said third thin film layer;
• and
• said reflector having a light reflectance of at least about 60% of light incident thereon at the wavelength region of about 550 nanometers and being achromatic.