Tokuhisa H, Tsukamoto S, Nobeshima T, Yamamoto N
Flexible Electronics Research Center, National Institute of Advanced Industrial Science and Technology Tsukuba Ibaraki Japan
RSC Adv. 2018 Apr 19;8(27):14864-14869. doi: 10.1039/c7ra11966f. eCollection 2018 Apr 18.
As an alternative to conventional indium-tin-oxide (ITO) electrodes, a transparent Cu grid electrode was fabricated by etching a sputtered Cu on a flexible polyethylene naphthalate film through a polyvinyl alcohol (PVA)-based protecting layer. The masking pattern of the PVA-based polymer on the Cu was generated by evaporation of an aqueous solution containing PVA-based polymers using a screen mesh as a template. The solution formed a stable liquid-bridge network between contact points of the screen mesh and the substrate after being dropped onto the mesh placed on the substrate. Drying of the solution yielded grid or dotted patterns, depending on the concentration of PVA. Etching of the Cu film covered with the PVA pattern was done with a FeCl methanolic solution to form a grid-patterned Cu electrode. Although some underetching was observed, adjusting the etching time gave a fine line network of Cu with the PVA coated thoroughly. The Cu grid electrode showed a transparency of 87.2 ± 5.2% at 550 nm and 6.1 ± 5.3 Ω □, which is comparable to or greater than that of the conventional ITO. Furthermore, we found that the PVA coating barrier significantly enhanced the oxidation resistance of the Cu grid electrode.
作为传统铟锡氧化物（ITO）电极的替代方案，通过在柔性聚萘二甲酸乙二酯薄膜上蚀刻溅射的铜，并通过基于聚乙烯醇（PVA）的保护层来制备透明铜网格电极。基于PVA的聚合物在铜上的掩膜图案是通过使用筛网作为模板蒸发含有PVA基聚合物的水溶液而产生的。将溶液滴到放置在基板上的筛网上后，溶液在筛网与基板的接触点之间形成稳定的液桥网络。溶液干燥后会产生网格或点状图案，这取决于PVA的浓度。用甲醇氯化铁溶液蚀刻覆盖有PVA图案的铜膜，以形成网格图案的铜电极。尽管观察到一些蚀刻不足，但通过调整蚀刻时间可以得到具有完全涂覆PVA的精细铜网线网络。铜网格电极在550nm处的透明度为87.2±5.2%，方阻为6.1±5.3Ω，与传统ITO相当或更高。此外，我们发现PVA涂层屏障显著提高了铜网格电极的抗氧化性。
