Tae Lim Jong, Lee Hyunkoo, Cho Hyunsu, Kwon Byoung-Hwa, Sung Cho Nam, Kuk Lee Bong, Park Jonghyurk, Kim Jaesu, Han Jun-Han, Yang Jong-Heon, Yu Byoung-Gon, Hwang Chi-Sun, Chu Lim Seong, Lee Jeong-Ik
Soft I/O Interface Research Section, Electronics and Telecommunications Research Institute, Daejeon 305-700, Korea.
IT Convergence Technology Research Laboratory, Electronics and Telecommunications Research Institute, Daejeon 305-700, Korea.
Sci Rep. 2015 Dec 2;5:17748. doi: 10.1038/srep17748.
Graphene has attracted considerable attention as a next-generation transparent conducting electrode, because of its high electrical conductivity and optical transparency. Various optoelectronic devices comprising graphene as a bottom electrode, such as organic light-emitting diodes (OLEDs), organic photovoltaics, quantum-dot LEDs, and light-emitting electrochemical cells, have recently been reported. However, performance of optoelectronic devices using graphene as top electrodes is limited, because the lamination process through which graphene is positioned as the top layer of these conventional OLEDs is a lack of control in the surface roughness, the gapless contact, and the flexion bonding between graphene and organic layer of the device. Here, a multilayered graphene (MLG) as a top electrode is successfully implanted, via dry bonding, onto the top organic layer of transparent OLED (TOLED) with flexion patterns. The performance of the TOLED with MLG electrode is comparable to that of a conventional TOLED with a semi-transparent thin-Ag top electrode, because the MLG electrode makes a contact with the TOLED with no residue. In addition, we successfully fabricate a large-size transparent segment panel using the developed MLG electrode. Therefore, we believe that the flexion bonding technology presented in this work is applicable to various optoelectronic devices.
石墨烯因其高导电性和光学透明性，作为下一代透明导电电极已引起了广泛关注。最近已有报道各种以石墨烯作为底部电极的光电器件，如有机发光二极管（OLED）、有机光伏电池、量子点发光二极管和发光电化学电池。然而，使用石墨烯作为顶部电极的光电器件性能受到限制，因为在这些传统OLED中将石墨烯定位为顶层的层压过程在表面粗糙度、无间隙接触以及石墨烯与器件有机层之间的弯曲键合方面缺乏控制。在此，通过干法键合，成功地将多层石墨烯（MLG）作为顶部电极植入到具有弯曲图案的透明OLED（TOLED）的顶部有机层上。具有MLG电极的TOLED的性能与具有半透明薄银顶部电极的传统TOLED相当，因为MLG电极与TOLED接触时无残留。此外，我们使用所开发的MLG电极成功制造了一个大尺寸透明分段面板。因此，我们相信这项工作中提出的弯曲键合技术适用于各种光电器件。
