Additive Solution-Processed Structural Colors

Abstract

Methods of forming a structural color metal-dielectric-metal (MDM) component via a solution-based process are provided. First, a first metal layer is formed over a treated surface of a substrate by a first electroless deposition process. A surface of the treated substrate is contacted with a first plating bath that comprises a metal selected from the group consisting of: copper, aluminum, silver, alloys, and combinations thereof. A dielectric layer, for example, comprising silicon dioxide, is then deposited over the first metal layer by a sol-gel process. Next, the method comprises forming a second metal layer over the dielectric layer by a second electroless deposition process by contacting the dielectric layer with a second plating bath having a neutral pH and comprising a metal selected from the group consisting of: copper, aluminum, silver, alloys, and combinations thereof.

What is claimed is: 
     
         1 . A method of forming a structural color metal-dielectric-metal (MDM) component, the method comprising:
 forming a first metal layer over a treated surface of a substrate by a first electroless deposition process by contacting a surface of the treated substrate with a first plating bath, wherein the first metal layer comprises a metal selected from the group consisting of: copper, aluminum, silver, titanium, manganese, iron, cobalt, gold, nickel, zinc, alloys, and combinations thereof;   depositing a dielectric layer over the first metal layer by a sol-gel process; and   forming a second metal layer over the dielectric layer by a second electroless deposition process by contacting the dielectric layer with a second plating bath having a pH of greater than or equal to about 6.5 to less than or equal to about 7.5, wherein the second metal layer comprises a metal selected from the group consisting of: copper, aluminum, silver, titanium, manganese, iron, cobalt, gold, nickel, zinc, alloys, and combinations thereof.   
     
     
         2 . The method of  claim 1 , wherein the first metal layer and the second metal layer independently have a thickness of greater than or equal to about 20 nm to less than or equal to about 200 nm. 
     
     
         3 . The method of  claim 1 , wherein the first metal layer has a first thickness of greater than or equal to about 20 nm to less than or equal to about 150 nm and the second metal layer has a second thickness of less than or equal to about 50 nm. 
     
     
         4 . The method of  claim 1 , wherein the first metal layer has a first morphology and the second metal layer has a second morphology that is distinct from the first morphology. 
     
     
         5 . The method of  claim 1 , wherein the dielectric layer has a thickness of greater than or equal to about 40 nm to less than or equal to about 150 nm. 
     
     
         6 . The method of  claim 1 , wherein the dielectric layer comprises a dielectric material selected from the group consisting of: silicon dioxide (SiO 2 ), silicon nitride (Si 3 N 4 ), other metal oxides and sulfides, including zinc oxide (ZnO), hafnium oxide (HfO 2 ), molybdenum trioxide (MoO 3 ), tantalum pentoxide (Ta 2 O 5 ), niobium pentoxide (Nb 2 O 5 ), oxide tungsten trioxide (WO 3 ), zinc selenide (ZnSe), zinc sulfide (ZnS), aluminum oxide (Al 2 O 3 ), magnesium fluoride (MgF 2 ), and combinations thereof. 
     
     
         7 . The method of  claim 1 , wherein the first metal layer and the second metal layer comprise copper and the dielectric layer comprises silicon dioxide (SiO 2 ). 
     
     
         8 . The method of  claim 1 , wherein the first metal layer and the second metal layer comprise copper and the dielectric layer comprises titanium dioxide (TiO 2 ). 
     
     
         9 . The method of  claim 1 , further comprising treating the surface of the substrate to form the treated substrate by a first silanizing process to form a first silanized surface followed by applying palladium nanocolloids over the first silanized surface. 
     
     
         10 . The method of  claim 9 , wherein the first silanizing process comprises exposing a surface of the substrate to 3-aminopropyltrimethoxysilane (APTMS). 
     
     
         11 . The method of  claim 9 , wherein the substrate is a plastic material and prior to the first silanizing process, treating the surface of the substrate with stearylmethylammonium chloride (SC). 
     
     
         12 . The method of  claim 1 , wherein the dielectric layer is a first dielectric layer and the method further comprises depositing a second dielectric layer over the second metal layer to form a metal-dielectric-metal-dielectric (MDMD) structure, where the second dielectric layer comprises a dielectric material selected from the group consisting of: silicon dioxide (SiO 2 ), silicon nitride (Si 3 N 4 ), other metal oxides and sulfides, including zinc oxide (ZnO), hafnium oxide (HfO 2 ), molybdenum trioxide (MoO 3 ), tantalum pentoxide (Ta 2 O 5 ), niobium pentoxide (Nb 2 O 5 ), oxide tungsten trioxide (WO 3 ), zinc selenide (ZnSe), zinc sulfide (ZnS), aluminum oxide (Al 2 O 3 ), magnesium fluoride (MgF 2 ), and combinations thereof. 
     
     
         13 . The method of  claim 1 , wherein the first plating bath comprises copper and formaldehyde (HCHO) and the first metal layer is formed by submerging the treated substrate in the first plating bath. 
     
     
         14 . The method of  claim 1 , wherein the dielectric layer comprises silicon dioxide (SiO 2 ) and the depositing of the dielectric layer comprises contacting the first metal layer on the treated substrate with a tetraethyl orthosilicate (TEOS) solution for the sol-gel process. 
     
     
         15 . The method of  claim 14 , wherein the contacting comprises submerging the first metal layer on the treated substrate in the TEOS solution and withdrawing the treated substrate from the TEOS solution at a constant rate equal or greater than 250 micrometers/second. 
     
     
         16 . The method of  claim 14 , further comprising drying the dielectric layer at a temperature of greater than or equal to about 70° C. 
     
     
         17 . The method of  claim 1 , wherein the dielectric layer comprises titanium dioxide (TiO 2 ) and the depositing of the dielectric layer comprises contacting the first metal layer on the treated substrate with a titanium tetraisopropoxide (TTIP) solution for the sol-gel process. 
     
     
         18 . The method of  claim 17 , wherein the contacting comprises submerging the first metal layer on the treated substrate in the TTIP solution and withdrawing the treated substrate from the TTIP solution at a constant rate equal or greater than 250 micrometers/second. 
     
     
         19 . The method of  claim 17 , further comprising drying the dielectric layer at a temperature of greater than or equal to about 70° C. 
     
     
         20 . The method of  claim 1 , further comprising treating the dielectric layer prior to the forming the second metal layer by conducting a second silanizing process of the dielectric layer to form a second silanized surface followed by applying palladium nanocolloids over the second silanized surface. 
     
     
         21 . The method of  claim 20 , wherein the second silanizing process comprises exposing the dielectric layer to 3-aminopropyltrimethoxysilane (APTMS). 
     
     
         22 . The method of  claim 1 , wherein the second plating bath comprises copper and dimethylamine-borane complex (DMAB) and the second metal layer is formed by submerging the treated substrate in the second plating bath.