Silver nanowire (AgNW) networks can exhibit very good electrical, thermal and optical properties, especially after thermal annealing. We have recently shown (Langley, Nanoscale 2014) the effects of a thermal annealing which allows: i) the formation of efficient percolating pathways; and ii) the local sintering at junctions between nanowires leading to a low electrical resistance.
Above a certain annealing temperature Rayleigh instability does occur thus destroying the percolative nature of AgNW networks.
Such networks can also efficiently act as transparent heaters.
A comprehensive model has been developed for describing the physics of such nanostructured transparent heaters (Sorel et al., ACS 2014).
a) Evolution of the electrical resistance of a AgNW network during a continuous thermal ramp; b-e) SEM images of: (b) as-deposited sample and of specimen annealed for 10 minutes at different temperatures: (c) 200°C, first occurrence of observable sintering; (d) 300 °C all junctions are sintered; (e) 380 °C complete spheroidization of the network. The scale bars in images b), c) and d) are 1 µm whereas that of image e) is 4 µm. (Ref: D.P. Langley et al. Nanoscale, to be published)
S. Sorel, D. Bellet, J.N. Coleman, The relationship between material properties and transparent heater performance for both bulk-like and percolative networks, ACS Nano 8 (2014) 4805
D.P. Langley, G. Giusti, M. Lagrange, R. Collins, C. Jimenez, Y. Bréchet, D. Bellet, Silver nanowire networks: physical properties and potential integration in solar cells, Solar Energy Materials & Solar Cells, 125 (2014) 318-324.
D.P. Langley, G. Giusti, C. Mayousse, C. Celle, D. Bellet, J.-P. SIimonato Flexible transparent conductive materials based on silver nanowire networks: a review, Nanotechnology 24 (2013) 452001055709.