Although graphene films have a strong potential to replace indium tin oxide anodes in organic light-emitting diodes (OLEDs), to date, the luminous efficiency of OLEDs with graphene anodes has been limited by a lack of efficient methods to improve the low work function and reduce the sheet resistance of graphene films to the levels required for electrodes1-4. Here, we fabricate flexible OLEDs by modifying the graphene anode to have a high work function and low sheet resistance, and thus achieve extremely high luminous efficiencies (37.2 lm W-1 in fluorescent OLEDs, 102.7 lm W -1 in phosphorescent OLEDs), which are significantly higher than those of optimized devices with an indium tin oxide anode (24.1 lm W -1 in fluorescent OLEDs, 85.6 lm W-1 in phosphorescent OLEDs). We also fabricate flexible white OLED lighting devices using the graphene anode. These results demonstrate the great potential of graphene anodes for use in a wide variety of high-performance flexible organic optoelectronics.
Bibliographical noteFunding Information:
This research was supported by the Basic Research Program and Global Frontier Research Center for Advanced Soft Electronics through the National Research Foundation of Korea (NRF), funded by the Ministry of Education, Science and Technology (nos. 2009-0067533, 2009-0075025, 2011-0006268 and 2009-0090177). This research was also supported by the Converging Research Center Program through the Ministry of Education, Science and Technology (no. 2010K001431).
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics