Reduced haze of transparent conductive films by smaller diameter silver nanowires

Abstract

Silver nanowires (Ag NWs) have received considerable attention for flexible transparent conductive films (TCFs) since they provide a relatively low sheet resistance at a high transmittance. However, the diffuse light scattering, haze, has been regarded as a hurdle to achieve clarity of films. Here we revisit the Mie scattering theory to calculate the extinction and scattering coefficients of Ag NWs which were employed to estimate haze of TCFs. The theory predicted a decrease in haze with a decrease in Ag NW diameter which was supported by experimental investigations carried out using Ag NWs with 5 different diameters (17.6, 19.9, 22.5, 24.3, and 29.6 nm). Overall, excellent properties of TCFs (haze = 0.21%-1.8%, transmittance = 95.33%-98.45%, sheet resistance = 20.87-81.76 Ω sq) were obtained. Ag NWs with a diameter of 17.6 nm provided minimum haze values at equivalent sheet resistances (e.g., haze = 0.21%, transmittance = 98.45%, sheet resistance = 77.36 Ω sq) compared with ones with lager diameters and the controls in literatures. This work investigated the interdependence between haze and NW diameter and might provide a design guide for flexible Ag NW TCFs.

Interdependence of Resistance and Optical Transmission in Conductive Nanowire Networks

“…In the introduction we noted the observation that T decreased linearly with the fraction of the network covered by nanowires; we note that this fraction is (1 – ε ), capturing the observed dependency. For completeness, we note the recent analysis of Menamparambath et al . who relate hazing for nanowires of different dimensions to the extinction coefficient and report haze values typically less than 2%.…”

Recent Progress on the Fabrication and Properties of Silver Nanowire-Based Transparent Electrodes

“…Based on the above, it seems straightforward to make a TE with high transmittance and low haze by using thin nanowires [ 75 ]. However, TEs with thin nanowires have lower thermal and chemical stability compared to those with thick nanowires, thereby shortening their lifetime.…”

New Insights into Flexible Transparent Conductive Silver Nanowires Films

“…Meanwhile, thinner AgNWs decrease the deposition area and light scattering, improving the optical transparency and haze of FTCFs [19,20]. The high aspect ratio of AgNWs enables electrical percolation without covering the whole substrate surface [19,20]. However, the large-scale synthesis of AgNWs with long length and small diameter is still difficult.…”

“…Generally, it is challenging to fabricate a high-performance AgNWs film with both high transmittance and high electrical conductivity, because AgNWs are not transparent. Meanwhile, the haze of AgNW-FTCFs strongly depends on the diameter of AgNWs and is decreased by using AgNWs with a smaller diameter [19,20,21]. High uniformity and low haze are two importance factors for high-end applications of the AgNWs–FTCFs.…”