Nanostructured Functional Coatings and Devices

Abstract

In one aspect of the present invention, an article including a nanostructured functional coating disposed on a substrate is described. The functional coating is characterized by both anti-reflection properties and down-converting properties. Related optoelectronic devices are also described.

1 . An article, comprising:
 a nanostructured functional coating disposed on a substrate, wherein the coating is characterized by both anti-reflection properties and down-converting properties.   
     
     
         2 . The article of  claim 1 , wherein the nanostructured functional coating comprises an anti-reflection layer. 
     
     
         3 . The article of  claim 2 , wherein the anti-reflection layer comprises an array of nano structures. 
     
     
         4 . The article of  claim 2 , wherein the anti-reflection layer has a uniform refractive index. 
     
     
         5 . The article of  claim 2 , wherein the anti-reflection layer has a graded refractive index in a direction substantially perpendicular to the substrate. 
     
     
         6 . The article of  claim 2 , wherein the anti-reflection layer comprises a lower region in contact with the substrate, and an upper region substantially opposite the lower region, and the refractive index of the array varies from a value, in the lower region, that substantially matches the refractive index of the substrate, to a higher value or a lower value, in a direction extending from the lower region to the upper region. 
     
     
         7 . The article of  claim 2 , wherein the anti-reflection layer comprises a transparent conductive material. 
     
     
         8 . The article of  claim 7 , wherein the transparent conductive material comprises a transparent conductive oxide, sulfide, phosphide, telluride, arsenide, nitride, or combination thereof. 
     
     
         9 . The article of  claim 2 , wherein the anti-reflection layer comprises a transparent non-conductive crystalline material. 
     
     
         10 . The article of  claim 2 , wherein the anti-reflection layer comprises a transparent non-conductive non-crystalline material. 
     
     
         11 . The article of  claim 1 , wherein the nanostructured functional coating comprises a down-converting material. 
     
     
         12 . The article of  claim 11 , wherein the down-converting material comprises a host and a dopant. 
     
     
         13 . The article of  claim 12 , wherein the host comprises a material selected from the group consisting of oxides, sulfides, borates, phosphates, silicates, flourides and oxyflourides, nitrides and oxynitrides, halides or combinations thereof. 
     
     
         14 . The article of  claim 12 , wherein the dopant comprises a rare-earth ion, a transition metal ion, or a lanthanide ion. 
     
     
         15 . The article of  claim 11 , wherein the down-converting material is present in the form of nanostructures. 
     
     
         16 . The article of  claim 15 , wherein the size of the nanostructures is in a range of from about 1 nanometer to about 500 nanometers. 
     
     
         17 . The article of  claim 16 , wherein the size of the nanostructures is in a range of from about 10 nanometers to about 100 nanometers. 
     
     
         18 . The article of  claim 15 , wherein the nano structured functional coating comprises an anti-reflection layer; and the nanostructures are embedded within the anti-reflection layer. 
     
     
         19 . The article of  claim 15 , wherein the nano structured functional coating comprises an anti-reflection layer; and the nanostructures are disposed below the anti-reflection layer. 
     
     
         20 . The article of  claim 3 , wherein the nanostructures in the anti-reflection layer are spaced from each other to form voids in the array of nanostructures, and down-converting nanostructures are located in substantially all of the voids of the array of nano structures. 
     
     
         21 . The article of  claim 11 , wherein the down-converting material is present in crystalline form. 
     
     
         22 . The article of  claim 21 , wherein the down-converting material comprises an array of nanostructures, each nanostructure having a substantially uniform cross-sectional area. 
     
     
         23 . The article of  claim 21 , wherein the down-converting material comprises an array of nanostructures, each nanostructure having a graded cross-sectional area. 
     
     
         24 . An optoelectronic device, comprising:
 a substrate;   a multi-layer structure disposed on the substrate; and   a nanostructured functional coating disposed on an electromagnetic radiation-receiving surface of the device, wherein the nanostructured functional coating is characterized by both anti-reflection properties and down-converting properties.   
     
     
         25 . The optoelectronic device of  claim 24 , wherein the multi-layer structure comprises one selected from the group consisting of a PN-junction, a hetero-junction, a quantum well, and a superlattice. 
     
     
         26 . The optoelectronic device of  claim 24 , in the form of a photovoltaic cell or a photovoltaic module. 
     
     
         27 . The optoelectronic device of  claim 24 , in the form of a photodiode, a camera, a light emitting diode device, or a display.