Synthesis and Purification of Silver Nanowires To Make Conducting Films with a Transmittance of 99%

Abstract

Metal nanowire (NW) networks have the highest performance of any solution-coatable alternative to ITO, but there is as yet no published process for producing NW films with optoelectronic performance that exceeds that of ITO. Here, we demonstrate a process for the synthesis and purification of Ag NWs that, when coated from an ink to create a transparent conducting film, exhibit properties that exceed that of ITO. The diameter, and thus optoelectronic performance, of Ag NWs produced by a polyol synthesis can be controlled by adjusting the concentration of bromide. Ag NWs with diameters of 20 nm and aspect ratios up to 2000 were obtained by adding 2.2 mM NaBr to a Ag NW synthesis, but these NWs were contaminated by nanoparticles. Selective precipitation was used to purify the NWs, resulting in a transmittance improvement as large as 4%. At 130.0 Ω sq(-1), the transmittance of the purified Ag NW film was 99.1%.

One-dimensional plasmonic hotspots located between silver nanowire dimers evaluated by surface-enhanced resonance Raman scattering

“…15 To start, 2.45 g of polyvinylpyrrolidone (PVP) was added to 60 ml of ethylene glycol (EG) and heated to solution was injected into the reactant. Then, 7.65 ml of 0.654 M silver nitrate solution was introduced into the reactant.…”

Extremely lightweight and ultra-flexible infrared light-converting quantum dot solar cells with high power-per-weight output using a solution-processed bending durable silver nanowire-based electrode

“…[39][40][41][42] The performance of the metal NW-based electrode generally increases with the decrease in the diameter of the NW, while the increase in the NW length/diameter aspect ratio will reduce light scattering and decrease the resistance in the film. [43][44][45][46][47][48][49] Therefore, in this study, Ag NWs with an average aspect ratio of 5000 (average diameter of B30 nm and length of 100-200 um, Fig. S1, ESI †) were utilized as the transparent and conductive front-electrodes in the flexible CQD solar cells.…”

Research Update: Synthesis of sub-15-nm diameter silver nanowires through a water-based hydrothermal method: Fabrication of low-haze 2D conductive films

“…These features make them ideal for use as transparent electrodes for flexible devices. [8][9][10][11][12][13]17,18 However, for device applications, some issues related to the fabrication of Ag NW network 2D films still need to be solved; these issues include the fact that they are easy to oxidize 15 and are subject to haziness due to light scattering 14 by the uneven surfaces of thick Ag NWs because constructing conductor films that have a junction between NW networks. In particular, in terms of the optical performance, their haze value is generally lower.…”

“…These studies were mainly focused on controlling the size, shape, crystal structure, and optical and electrical properties of the Ag NWs. Recently, Wiley et al 17 reported that Ag NWs with diameters of approximately 20 nm and aspect ratios up to 2000 can be synthesized by optimizing the bromide ion concentration used in the conventional polyol method. Our group has also contributed to this field of study by reporting on thin Ag NWs with an average diameter of 20 nm and length of 22 µm, which were developed using a pressure-induced polyol method.…”