Current distribution in conducting nanowire networks

Abstract

Conducting nanowire networks find diverse applications in solar cells, touch-screens, transparent heaters, sensors, and various related transparent conducting electrode (TCE) devices. The performances of these devices depend on effective resistance, transmittance, and local current distribution in these networks. Although, there have been rigorous studies addressing resistance and transmittance in TCE, not much attention is paid on studying the distribution of current. Present work addresses this compelling issue of understanding current distribution in TCE networks using analytical as well as Monte-Carlo approaches. We quantified the current carrying backbone region against isolated and dangling regions as a function of wire density (ranging from percolation threshold to many multiples of threshold) and compared the wired connectivity with those obtained from template-based methods. Further, the current distribution in the obtained backbone is studied using Kirchhoff's law, which reveals that a significant fraction of the backbone (which is believed to be an active current component) may not be active for end-to-end current transport due to the formation of intervening circular loops. The study shows that conducting wire based networks possess hot spots (extremely high current carrying regions) which can be potential sources of failure. The fraction of these hot spots is found to decrease with increase in wire density, while they are completely absent in template based networks. Thus, the present work discusses unexplored issues related to current distribution in conducting networks, which are necessary to choose the optimum network for best TCE applications.

Effective resistance of random percolating networks of stick nanowires: Functional dependence on elementary physical parameters

“…the current carrying fraction of the wires, as done for instance in Ref. 16,25 , as a function of varying physical parameters (i.e. of varying resistance of the individual components of the network) could also prove useful for sensor applications, to localise the most active sensing areas in the network.…”

Transparent electrodes with nanorings: A computational point of view

“…Numerous works have been devoted to the electrical and optical properties of transparent films with elongated fillers such as NTs, NWs, and nanorods. [3][4][5][6][7][8][9][10][11][12][13][14] However, the use of films containing conducting nanorings [15][16][17] looks extremely attractive since, in this case, there are no dead ends in the percolation cluster, i.e., the percolation cluster is identical to its geometrical backbone. In a two-dimensional continuum percolation, the number density is defined as where N is the number of objects randomly deposited onto a square substrate of size L×L with periodic boundary conditions (PBC).…”

Percolation of sticks: Effect of stick alignment and length dispersity

“…Percolation, i.e., the occurrence of a connected subset (a cluster) within a disordered medium which spans its opposite borders, has attracted the attention of the scientific community over several decades [1][2][3][4][5]. Nowadays, two-dimensional (2D) systems such as transparent electrodes present examples of where highly conductive particles, e.g., nano-wires (NWs), nano-tubes (NTs), and nano-rods (NRs), form a random resistor network (RRN) inside a poorly conductive host matrix (substrate) [6][7][8]. The appearance of a percolation cluster in this kind of systems drastically changes their physical properties and is associated with an insulator-to-conductor phase transition.…”