Method for making a graded barrier coating
View Patent ↗Disclosed is a method relating to graded-composition barrier coatings comprising first and second materials in first and second zones. The compositions of one or both zones vary substantially continuously across a thickness of the zone in order to achieve improved properties such as barrier, flexibility, adhesion, optics, thickness, and tact time. The graded-composition barrier coatings find utility in preventing exposure of devices such as organic electro-luminescent devices (OLEDs) to reactive species found in the environment.
1. A method of forming a barrier coating, the method comprising:
providing a device having a surface; and
depositing on said surface a graded-composition barrier coating comprising:
a first zone defined by a first thickness comprising a first material and a second material wherein a composition of said first zone varies substantially continuously across said first thickness; and
a second zone defined by a second thickness which is substantially free of any of said first material; and,
wherein said coating is deposited using a method selected from the group consisting of: sputtering, reactive sputtering, evaporation, plasma-enhanced chemical vapor deposition, reactive ion etching plasma-enhanced chemical vapor deposition, radio-frequency plasma-enhanced chemical-vapor deposition, expanding thermal plasma chemical-vapor deposition, electron-cyclotron-resonance plasma-enhanced chemical-vapor deposition, inductively-coupled plasma-enhanced chemical-vapor deposition, and combinations thereof.
2. The method of claim 1 , wherein said first material is organic and second material is inorganic.
3. The method of claim 1 , Wherein said first material and said second material are each inorganic.
4. The method of claim 1 , wherein a percent atomic Carbon in said first zone does not exceed approximately 90%.
5. The method of claim 1 , wherein a percent atomic Carbon in said second zone does not exceed approximately 5%.
6. The method of claim 1 , wherein said coating has optical properties that are substantially uniform along an axis of light transmission, said axis oriented substantially perpendicular to the surface of the coating.
7. The method of claim 1 , wherein said first thickness is between approximately 5 nm and approximately 1000 nm.
8. The method of claim 1 , wherein said coating comprises a material selected from a group consisting of: organic, inorganic, ceramic, and combinations thereof.
9. The method of claim 8 wherein the inorganic and ceramic materials are selected from the groups consisting of: oxide, nitride, carbide, boride, and combinations thereof of elements of Group IIA, IIIA, IVA, VA, VIA, VIIA, IB, and IIB, metals of group IIIB, IVB, and VB, and rare-earth metals.
10. The method of claim 8 , wherein said organic material comprises a material selected from the group consisting of: a polymer, parylene, an acrylic, a siloxane, xylene, an alkene, styrene, an organosilane, an organsilazane, an organosilicone, and combinations thereof.
11. The method of claim 8 , wherein the organic material comprises material from the group consisting of: metal oxide, metal nitride, silicon oxide, silicon nitride, metal oxynitride, silicon oxynitride, and combinations thereof.
12. The method of claim 1 , wherein said coating is substantially transparent.
13. The method of claim 1 , wherein said device is selected from the group consisting of: an electrochromic device, a liquid crystal display, an organic light emitting diode, a light emitting diode, a photovoltaic device, a radiation detector, an integrated circuit, a sensor, a component of a medical diagnostic system and combinations thereof.
14. The method of claim 1 further comprising a substrate upon which said device is disposed.
15. The method of claim 14 , wherein said substrate is substantially flexible.
16. The method of claim 14 , wherein said substrate is substantially transparent.
17. The method of claim 14 , wherein said substrate comprises a material selected from the group consisting of: plastics, glass, and metal.
18. The method of claim 1 further comprising a substrate upon which said coating is disposed.
19. The method of claim 1 , wherein said device is encapsulated by said coating or by said coating and a substrate.
20. The method of claim 1 , wherein said coating has an oxygen transmission rate less than approximately 0.01 cm 3 /(m 2 day) as measured at 25° C. with gas having approximately 21 volume-percent oxygen.
21. The method of claim 1 , wherein said coating has a water vapor transmission rate less than approximately 0.0001 g/(m 2 day), as measured at 25° C. with gas having approximately 100-percent relative humidity.
22. The method of claim 1 , wherein said first zone and said second zone are contiguous.
23. A method of framing a barrier coating, the method comprising:
providing a substrate;
providing an electronic device disposed on said substrate; and
depositing on said electronic device via plasma-enhanced chemical-vapor deposition a graded-composition barrier coating which is substantially transparent to visible light, wherein said coating comprises:
a first zone defined by a first thickness in which a composition of an inorganic material and a composition of an organic material each vary substantially continuously across said first thickness and wherein said first thickness is between approximately 5 nm and approximately 1000 nm; and
a second zone defined by a second thickness which is substantially free of any organic material.
24. The method of claim 23 , wherein said coating has an oxygen transmission rate less than approximately 0.01 cm 3 /(m 2 day) as measured at 25° C. with gas having approximately 21 volume-percent oxygen and wherein said coating has a water vapor transmission rate less than approximately 0.0001 g/(m 2 day), as measured at 25° C. with gas having approximately 100-percent relative humidity.
25. The method of claim 24 wherein said coating has optical properties that are substantially uniform along an axis of light transmission, said axis oriented substantially perpendicular to the surface of the coating.
26. The method of claim 24 wherein said coating comprises a material selected from the group consisting of: organic, inorganic, ceramic, and combinations thereof.
27. The method of claim 24 , wherein said device is selected from the group consisting of: an electrochromic device, a liquid crystal display, an organic light emitting diode, a light emitting diode, a photovoltaic device, a radiation detector, an integrated circuit, a sensor, a component of a medical diagnostic system and combinations thereof.
28. The method of claim 24 , wherein said substrate is substantially flexible.
29. The method of claim 24 , wherein said substrate is substantially transparent.
30. The method of claim 24 , wherein said device is encapsulated by said coating or by said coating and said substrate.
31. The method of claim 24 , wherein said first zone and said second zone are contiguous.