Graphene/silver nanowire sandwich structures for transparent conductive films

We report a simple graphene/silver nanowire (AgNW)/graphene sandwich structure that can be used to prepare highly transparent conductive films; the electrical conductivity of this structure is superior to those of pure AgNW or graphene/AgNW films. Upon increasing the graphene content, the ratio of the direct current (DC) conductivity to the optical conductivity of the three-layer graphene/AgNW/graphene film increased from 4.7 to 44, primarily as a result of connecting and clipping effects. At low contents of AgNW, the graphene played a role of connecting the AgNWs, thereby increasing the DC conductivity by nearly seven orders of magnitude relative to that of pure AgNW films; when the AgNW content was high, the DC conductivity was also enhanced, by 23.8-fold. Observing the second-order zone-boundary phonons, the enhancement in conductivity resulted mainly from tighter contact between the AgNWs, arising from restacldng of the top and bottom graphene sheets. (C) 2013 Elsevier Ltd. All rights reserved.