Electrodeposited Silver Nanowire Transparent Conducting Electrodes for Thin-Film Solar Cells

Abstract

Silver nanowire (AgNW) networks have demonstrated high optical and electrical properties, even better than those of indium tin oxide thin films, and are expected to be a next-generation transparent conducting electrode (TCE). Enhanced electrical and optical properties are achieved when the diameter of the AgNWs in the network is fairly small, that is, typically less than 30 nm. However, when AgNWs with such small diameters are used in the network, stability issues arise. One method to resolve the stability issues is to increase the diameter of the AgNWs, but the use of AgNWs with large diameters has the disadvantage of causing a rough surface morphology. In this work, we resolve all of the aforementioned issues with AgNW TCEs by the electrodeposition of Ag onto as-spin-coated thin AgNW TCEs. The electrodeposition of Ag offers many advantages, including the precise adjustment of the AgNW diameter and wire-to-wire welding to improve the junction conductance while minimizing the increase in protrusion height because of the overlap of AgNWs upon increasing the diameter. In addition, Ag electrodeposition on AgNW TCEs can provide higher conductance than that of as-spin-coated AgNW TCEs at the same transparency because of the reduced junction resistance, which generates a superior figure of merit. We applied the electrodeposited (ED) AgNW network to a Cu­(In,Ga)­Se2 thin-film solar cell and compared the device performance to a device with a standard sputtered transparent conducting oxide (TCO). The cell fabricated by the electrodeposition method showed nearly equal performance to that of a cell with the sputtered TCO. We expect that ED AgNW networks can be used as high-performance and robust TCEs for various optoelectronic applications.

Silver Nanowire Synthesis and Strategies for Fabricating Transparent Conducting Electrodes

“…In 2019, Lee et.al. used electrodeposition of silver ions on spin coated AgNW TCE and demonstrated that this technique can enhance various optoelectronic properties such as electrical conductivity, optical transmittance, high temperature stability along with low junction height and sheet resistance [240]. Consequently, the obtained a TCE with a transmittance more than 93% and sheet resistance of 14 Ω/sq as shown in Figure 21f,g.…”

“…In 2019, Lee et.al. used electrodeposition of silver ions on spin coated AgNW TCE and demonstrated that this technique can enhance various optoelectronic properties such as electrical conductivity, optical transmittance, high temperature stability along with low junction height and sheet resistance [240]. Consequently, the obtained a TCE with a transmittance more than 93% and sheet resistance of 14 Ω/sq as shown in Figure 21f Recently, a highly flexible, transparent and conductive electrode with a negligible junction height was fabricated using spray coating under the application of low DC voltage (3.6-6.0 V) as shown in Figure 21b [238].…”

“…(g) FoMs for AgNW networks with initial diameters 80 nm. The FoMs of the ED AgNW networks are superior to those of the as-spin-coated AgNW networks (adapted from [240] with permission from ACS publications, 2020).…”

Fabrication of reduced graphene oxide modified poly(3,4-ethylenedioxythiophene) polystyrene sulfonate based transparent conducting electrodes for flexible optoelectronic application

“…Transparent conducting electrode (TCE) is an essential part of various optoelectronic devices such as lightemitting diodes, photovoltaic cells, touch screens, solar cells, and flat-panel displays [1][2][3]. Among various TCEs, Indium tin oxide (ITO) is most preferred as it wealth with attracting characteristics like high transmittance (~ 90%) and low sheet resistance (~ 10 Ω/sq.)…”

Modification of Silver Nanowire Coatings with Intense Pulsed Ion Beam for Transparent Heaters

“…However, ITO application is limited by the high fabrication cost, while its brittleness makes it unsuitable for flexible electronics. Various alternative materials, such as carbon nanotubes [4,5], graphene [6,7], conductive polymers [8,9], and metallic nanowires [10,11] are being explored, among which silver nanowires (AgNWs) have attracted special attention because of their high electrical conductivity, high transparency, and excellent mechanical properties [1][2][3][12][13][14]. The most commonly used method of AgNWs synthesis is the polyol method, which is a simple, yet highly controllable liquid-phase process that does not require expensive equipment [15][16][17][18].…”