RLE Recent Papers

Characterizing Percolative Materials by Straining

Heming Yao, Marek Hempel, Ya-Ping Hsieh, Jing Kong, and Mario Hofmann

DOI: 10.1039/C8NR09120J 

Abstract:

Carrier transport in a wide range of nanomaterial assemblies proceeds by percolation through discontinuous networks of constituents. Improving percolative nanomaterials could enhance transparent conductors, sensors, and electronic devices. A significant obstacle in optimizing percolative materials is the challenge in their characterization. The critical connection pathways which determine a percolative material’s conductivity are not easily accessible with existing metrology tools and traditional investigation approaches relied on indirect methods based on many samples and on simplifying assumptions. We here demonstrate the direct extraction of characteristic parameters from a single sample by analyzing the strain-dependent resistance of a percolative materials. An analytical model is derived that can explain experimental data for various percolative materials, morphologies, and straining conditions. Relation of the extracted parameters to previously introduced figures of merits allows us to compare nanostructures of diverse dimensionality and composition for applications such as for strain gauges and transparent conductors.