차세대 롤러블 전자 소자용 투명 하이브리드 전극

Abstract

Mechanically durable transparent electrodes are needed in flexible electronic devices to implement their long-term stable operating for applications in bendable, foldable and rollable fields. As it is well-known, Indium-tin-oxide (ITO), which is most typically used as a transparent electrode, is not suitable to be applied to flexible substrates because of its rigid property. As such, several promising transparent electrodes have been previously reported replacing ITO. Among these, metal mesh has various advantages while being applicable to flexible substrate. First, desired transmittance and conductivity can be obtained by controlling line width, line spacing, pitch and thickness. Second, it is possible to manufacture a variety of materials by changing the metal material according to the manufacturing method. However, the produced sample has a surface roughness despite being in the form of embedding and metal mesh has inherent voids problem. Herein, we designed hybrid electrode constitute of metal mesh with poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) to compensate that several problems. In the case of a metal mesh, after patterning by photolithography on a flat substrate, electrodes were formed by electroplating and transferred to a flexible substrate. The hybrid electrode could be easily manufactured by spin coating PEDOT:PSS on the metal mesh. As a result, the hybrid electrode of the metal mesh and PEDOT:PSS had a transmittance over than 80% at 550 nm, and a sheet resistance of 0.23 Ω/sq. Moreover, the hybrid electrode can maintain its highly mechanical durability even after a bending and rolling tests. Due to the excellent mechanical properties of the hybrid electrode, the transparent film heater and organic solar cell manufactured based on the hybrid electrode, that were very stable in mechanical properties.