Conductive sol–gel films

Abstract

We report that silver nanowires (AgNW) entrapped in a series of sol–gel thin films – zirconia, alumina, titania and silica – provide conductive, highly flexible, highly adhesive, transparent thin films with excellent thermal and electrical stability. These films were subjected to intensive study and characterization including resistance, percolation analysis, critical bending angle analysis, critical thermal stability, transparency, and more. Remarkably, when resistance is kept constant, all of the studied parameters follow the same order – either increasing or decreasing – of ZrO₂, SiO₂, Al₂O₃, and TiO₂. A detailed interpretation, based on the particle-sizes of the elementary sol–gel building blocks, is provided. In particular we found that the AgNWs re-enforce the ceramic matrices, thus providing excellent electroconductive stability with low silver concentration and high degree of homogeneity of the dopant distribution. Having in mind that current materials for films with these properties are often accompanied by disadvantages (such as brittleness, scarcity and poor adhesion) we offer the new conductive films as an interesting alternative to be considered.