New Insights into Flexible Transparent Conductive Silver Nanowires Films.

Xing Yang,Xianfeng Zhang,Yuzhen Zhao,Dexi Du,Yuehui Wang

doi:10.3390/ijms20112803

Abstract

Flexible transparent conductive films (FTCFs) composed of silver nanowires (AgNWs) have become an important research direction because of their potential in flexible electronic devices. The optoelectronic properties of FTCFs composed of AgNWs of different lengths were evaluated in this study. AgNWs, with an average diameter of about 25 nm and length of 15.49–3.92 μm were obtained by a sonication-induced scission process. AgNW-FTCFs were prepared on polyethylene terephthalate substrates using a Meyer bar and then dried in the ambient environment. The sheet resistance, non-uniformity factor of the sheet resistance, the root mean square roughness, and haze of the FTCFs increased as the length of AgNWs decreased. The transmittance of the films increased slightly as the length of AgNWs increased. AgNWs with a length of 15.49 μm provided an AgNW-FTCF with excellent properties including haze of 0.95%, transmittance of 93.42%, and sheet resistance of 80.15 Ω∙sq−1, without any additional post-treatment of the film. This work investigating the dependence of the optoelectronic properties of AgNW-FTCFs on AgNW length provides design guidelines for development of AgNW-FTCFs.

Highlights

As the demand for flexible and wearable electronic devices has increased over the last 20 years, the development of the flexible transparent conducting films (FTCFs) with excellent electrical conductivity, flexibility, and optical transparency has become important
The conductive networks of AgNW-FTCFs are only composed of AgNWs and pores, and several studies have indicated that the properties of AgNW-FTCFs are defined mainly by the size, aspect ratio, and purity of AgNWs, contact between AgNWs and network morphology [16,17,18]
AgNW-FTCFs were prepared on PET substrates and dried in the ambient environment

Summary

Introduction

As the demand for flexible and wearable electronic devices has increased over the last 20 years, the development of the flexible transparent conducting films (FTCFs) with excellent electrical conductivity, flexibility, and optical transparency has become important. Longer AgNWs may form a network with longer conducting paths, lower deposition density and a decreased number of junctions between AgNWs, which lowers junction resistance These factors indicate that longer AgNWs can improve the conductivity of FTCFs. thinner AgNWs decrease the deposition area and light scattering, improving the optical transparency and haze of FTCFs [19,20]. Sorel et al measured the transmittance and sheet resistance for a large number of networks of AgNWs with different lengths and diameters [24] They found that the network direct current conductivity scaled linearly with wire length, whereas the optical conductivity remained approximately constant regardless of nanowire length. The resulting FTCF composed of 15.5 μm AgNWs has high transparency, low sheet resistance and haze and root mean square roughness, and high uniformity. We would like to point out that the AgNW-FTCFs conductive film prepared have no any additional post-treatment

Sonication-Induced Scission of Silver Nanowires

Characterization

Conclusions