Nanowire structured color filter arrays and fabrication method of the same

Abstract

Color filter array devices and methods of making color filter array devices are disclosed herein. A color filter array may include a substrate having a plurality of pixels thereon, one or more nanowires associated with each of the plurality of pixels, wherein each of the one or more nanowires extends substantially perpendicularly from the substrate, and an optical coupler associated with each of the one or more nanowires. A method of making a color filter array may include, making an array of nanowires, wherein each of the nanowires extend substantially perpendicularly from a substrate, disposing a transparent polymer material to substantially encapsulate the nanowires, removing the nanowires from the substrate, providing a pixel array comprising a plurality of pixels, wherein a hard polymer substantially covers an image plane of the pixel array, disposing the array of nanowires on the pixel array, and removing the transparent polymer encapsulating the nanowires.

What is claimed: 
     
         1 . A color filter array comprising:
 a substrate having a plurality of pixels thereon;   one or more nanowires associated with each of the plurality of pixels, wherein each of the one or more nanowires extends substantially perpendicularly from the substrate; and   an optical coupler associated with each of the one or more nanowires.   
     
     
         2 . The color filter array of  claim 1 , wherein each of the one or more nanowires is configured to absorb a fundamental frequency of light, the fundamental frequency being correlated with a diameter of the nanowire. 
     
     
         3 . The color filter array of  claim 2 , wherein each of the one or more nanowires are further configured to absorb an n th  harmonic frequency corresponding to the fundamental frequency of light, wherein n is an integer greater than one. 
     
     
         4 . The color filter array of  claim 2 , wherein the one or more nanowires have a diameter smaller than about 50 nm for absorbing wavelengths in ultraviolet (UV) region of electromagnetic spectrum. 
     
     
         5 . The color filter array of  claim 2 , wherein the one or more nanowires have a diameter of about 50 nm to about 75 nm for absorbing wavelengths in blue region of electromagnetic spectrum. 
     
     
         6 . The color filter array of  claim 2 , wherein the one or more nanowires have a diameter of about 75 nm to about 100 nm for absorbing wavelengths in green region of electromagnetic spectrum. 
     
     
         7 . The color filter array of  claim 2 , wherein the one or more nanowires have a diameter of about 90 nm to about 120 nm for absorbing wavelengths in red region of electromagnetic spectrum. 
     
     
         8 . The color filter array of  claim 2 , wherein the one or more nanowires have a diameter larger than about 115 nm for absorbing wavelengths in infrared (IR) region of electromagnetic spectrum. 
     
     
         9 . The color filter array of  claim 1 , wherein the substrate comprises an image sensor including a charge-coupled device (CCD) array or a complementary metal-oxide-semiconductor (CMOS) sensor array. 
     
     
         10 . The color filter array of  claim 1 , wherein the one or more nanowires have a diameter of about 50 nm to about 200 μm. 
     
     
         11 . The color filter array of  claim 1 , wherein the one or more nanowires have a cross-sectional shape of circle, ellipse, regular polygon, irregular polygon, or any combination thereof. 
     
     
         12 . The color filter array of  claim 1 , wherein the one or more nanowires have a length of about 0.1 μm to about 10 μm. 
     
     
         13 . The color filter array of  claim 1 , wherein the plurality of pixels form an array having a pre-determined shape and a pitch of about 0.2 μm to about 20 μm. 
     
     
         14 . The color filter array of  claim 13 , wherein the one or more nanowires form an array having substantially the same shape and pitch of the array formed by the plurality of pixels. 
     
     
         15 . The color filter array of  claim 1 , wherein the optical coupler is configured to guide radiation into the nanowires. 
     
     
         16 . The color filter of  claim 1 , wherein the optical coupler comprises a microlens or a coupler disposed on an end of each of the one or more nanowire away from the substrate. 
     
     
         17 . The color filter of  claim 1 , wherein the one or more nanowires comprise one or more of silicon (Si), germanium (Ge), boron phosphide (BP), boron arsenide (BAs), aluminum phosphide (AlP), aluminum arsenide (AlAs), aluminum antimonide (AlSb), gallium nitride (GaN), gallium phosphide (GaP), gallium arsenide (GaAs), gallium antimonide (GaSb), indium nitride (InN), indium phosphide (InP), indium arsenide (InAs), zinc oxide (ZnO), zinc sulfide (ZnS), zinc selenide (ZnSe), zinc telluride (ZnTe), cadmium sulfide (CdS), cadmium selenide (CdSe), and cadmium telluride (CdTe). 
     
     
         18 . A device comprising nanowires, wherein the nanowires extend substantially perpendicularly from a substrate and are etched from the substrate; a pixel array comprising a plurality of pixels; wherein the nanowires are disposed on the pixel array; wherein the nanowires are made by creating an array of dots on the substrate and forming the nanowires by etching the substrate, wherein shapes and sizes of the dots determine the cross-sectional shapes and sizes of the nanowires. 
     
     
         19 . The device of  claim 18 , further comprising a transparent polymer substantially encapsulating the nanowires. 
     
     
         20 . The device of  claim 18 , further comprising a hard polymer substantially covering an image plane of the pixel array.