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

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 NVVs 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 NVsTs were contaminated by nanopartides. Selective precipitation was used to purify the NWs, resulting in a transmittance improvement as large as 4%. At 130.0 Omega sq(-1), the transmittance of the purified Ag NW film was 99.1%.