Graphene/metal nanowire hybrid transparent conductive films

Abstract

A hybrid transparent conductive film, and methods for fabricating such hybrid transparent conductive films, involving the assembly of two-dimensional graphene-based materials with one-dimensional silver and/or copper nanowires with high optical transmittance and good electrical conductivity. The hybrid films are characterized by a good degree of control of the architecture at the nanoscale level, where the weakness(es) of each component are offset by the strengths of the other components. By rational design of the structure and using simple and locate-cost fabrication methods, hybrid films with sheet resistance of 26 ohm/sq and optical transmittance (at λ=550 nm) of 83% for reduced graphene oxide/silver nanowire films, and 64 ohm/sq and optical transmittance of 93.6% for monolayer graphene/silver nanowire films have been fabricated. These values are comparable to transparent conductive films based on indium tin oxide but are now able to be used in flexible electronics due to their good mechanical properties.

1 . An electrochromic device, comprising:
 a first layer of a glass substrate;   a graphene/silver nanowire film residing on top of said first layer of said glass substrate;   a buffer layer of tungsten trioxide film on top of said graphene/silver nanowire film;   a layer of sol-gel tungsten trioxide film residing on top of said buffer layer of tungsten trioxide film;   an electrolyte residing on said layer of sol-gel tungsten trioxide film;   an indium tin oxide layer residing on said electrolyte; and   a second layer of a glass substrate residing on said indium tin oxide layer.   
     
     
         2 . The electrochromic device as recited in  claim 1 , wherein said electrolyte comprises a Liconductive electrolyte. 
     
     
         3 . The electrochromic device as recited in  claim 1 , wherein said electrolyte comprises a propylene/ethylene carbonate solution (1:1) containing 1 M lithium perchlorate. 
     
     
         4 . The electrochromic device as recited in  claim 1 , wherein said buffer layer of tungsten trioxide film has a thickness of approximately 100 nm. 
     
     
         5 . The electrochromic device as recited in  claim 1 , wherein a thickness of a combination of said buffer layer of tungsten trioxide film and said layer of sol-gel tungsten trioxide film is approximately 500 nm. 
     
     
         6 . The electrochromic device as recited in  claim 1 , wherein said graphene/silver nanowire film and said indium tin oxide layer function as electrodes. 
     
     
         7 . The electrochromic device as recited in  claim 1 , wherein a combination of said buffer layer of tungsten trioxide film and said layer of sol-gel tungsten trioxide film are used as an electrochromic layer of said electrochromic device.