Extracting the Temperature Dependence of Both Nanowire Resistivity and Junction Resistance from Electrical...

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.