Extracting the Temperature Dependence of Both Nanowire Resistivity and Junction Resistance from Electrical Measurements on Printed Silver Nanowire Networks.

Abstract

Printed networks of nanoparticles (e.g., nanodots, nanowires, nanosheets) are important for a range of electronic, sensing and energy storage applications. Characterizing the temperature dependence of both the nanoparticle resistivity (ρ_NW) and interparticle junction resistance (R _J) in such networks is crucial for understanding the conduction mechanism and so for optimizing network properties. However, it is challenging to extract both ρ_NW and R _J from standard electrical measurements. Here, using silver nanowires (AgNWs) as a model system, we describe a broadly applicable method to extract both parameters from resistivity measurements on nanowire networks. We achieve this by combining a simple theoretical model with temperature-dependent resistivity measurements on sets of networks fabricated from nanowires of different lengths. As expected, our results demonstrate that R _J is the predominant bottleneck for charge transport within these networks, with R _NW/R _J in the range 0.03-0.7. We demonstrate that the temperature dependence of ρ_NW exhibits characteristic Bloch-Grüneisen behavior, yielding a Debye temperature between 133-181 K, which aligns with reported values for individual nanowires. Likewise, our findings for residual resistivity and electron-phonon coupling constants closely match published values measured on individual nanowires. The junction resistance also follows Bloch-Grüneisen behavior with similar parameters, indicating the junctions consist of metallic silver. These findings confirm the validity of our method and provide a deeper insight into the conduction mechanisms in AgNW networks. They also pave the way toward simultaneous measurement of ρ_NW and R _J in other important systems, notably carbon nanotube networks.