Scratch-resistant and optically transparent materials and articles
Embodiments of a scratch-resistant and optically transparent material comprising silicon, aluminum, nitrogen, and optionally oxygen are disclosed. In one or more embodiments, the material exhibits an extinction coefficient (k) at a wavelength of 400 nm of less than about 1×10 −3 , and an average transmittance of about 80% or greater, over an optical wavelength regime in the range from about 380 nm to about 780 nm, as measured through the material having a thickness of about 0.4 micrometer. In one or more embodiments, the material comprises an intrinsic maximum hardness of about 12 GPa or greater as measured on a major surface of the material having a thickness of about 400 by a Berkovich Indenter Hardness Test along an indentation depth of about 100 nm or greater, low compressive stress and low roughness (Ra). Articles and devices incorporating the material are also disclosed.
1. An optically transparent material comprising:
a composition comprising silicon, aluminum, and nitrogen;
an extinction coefficient (k) at a wavelength of 400 nm of less than about 1×10 −3 , and an average transmittance of about 80% or greater, over an optical wavelength regime in the range from about 380 nm to about 780 nm, as measured through the material having a thickness of about 2 micrometers;
an intrinsic maximum hardness of about 12 GPa or greater as measured on a major surface of the material having a thickness of about 400 nm by a Berkovich Indenter Hardness Test along an indentation depth of about 100 nm or greater,
wherein the composition comprises silicon in an amount in a range from about 0.1 atomic % to about 30 atomic %.
2. The optically transparent material of claim 1 , wherein the composition further comprises oxygen.
3. The optically transparent material of claim 1 , wherein at least one of:
the material comprises a refractive index of about 2.0 or greater, as measured at a wavelength of 550 nm; and
the material comprises a roughness (Ra) of less than 1.5 nm as measured by atomic force microscopy on the major surface along an imagining area having dimensions of 2 micrometers by 2 micrometers.
4. A optically transparent material comprising:
a composition comprising silicon, wherein silicon is present in an amount of about 25 atomic % or less, aluminum, oxygen in an amount of in the range from about 0 atomic % to about 15 atomic %, and nitrogen;
an average transmittance of about 80% or greater, over an optical wavelength regime in the range from about 380 nm to about 780 nm, as measured through the material having a thickness of 2 micrometers;
an intrinsic maximum hardness of about 12 GPa or greater as measured on a major surface of the material having a thickness of about 400 nm by a Berkovich Indenter Hardness Test along an indentation depth of about 100 nm or greater.
5. The material of claim 4 , wherein the optically transparent material comprises silicon in an amount in a range from about 5 atomic % to about 25 atomic %, aluminum in an amount in a range from about 25 atomic % to about 45 atomic %, oxygen in an amount in a range from about 0 atomic % to about 15 atomic %, and nitrogen in an amount in a range from about 35 atomic % to about 50 atomic %.
6. The material of claim 4 , wherein the composition comprises at least about 0.1 atomic % oxygen.
7. The optically transparent material of claim 4 , wherein at least one of:
the material comprises an extinction coefficient (k) at a wavelength of 400 nm of less than about 1×10 −3 , as measured through the material having a thickness of about 400 nm;
the material comprises a refractive index of about 2.0 or greater, as measured at a wavelength of 550 nm; and
the material comprises a roughness (Ra) of less than 1.5 nm as measured by atomic force microscopy on the major surface along an imagining area having dimensions of 2 micrometers by 2 micrometers.
8. The optically transparent material of claim 1 , wherein the composition comprises aluminum in an amount in a range from about 25 atomic % to about 44 atomic % and nitrogen in an amount in a range from about 36 atomic % to about 50 atomic %.
9. The optically transparent material of claim 4 , wherein the composition comprises aluminum in an amount in a range from about 25 atomic % to about 44 atomic % and nitrogen in an amount in a range from about 36 atomic % to about 50 atomic %.