Date

Place

Room B (Room 324)
49. OLED Optics
August 21, 2015 (Friday)
11:00 ~ 12:35

[49-3]
11:40 ~ 11:55
Title:Enhanced Efficiency of Organic Light-Emitting Diodes Using TiO2 Nanoparticles via a Microcavity Effect
Jun Hee Han, Do-Hong Kim, and Kyung Cheol Choi (KAIST, Korea)
Abstract: In this study, we have used TiO2 nanoparticles to increase the microcavity effect that occurs inside the OLED to obtain improved optical efficiency. TiO2 nanoparticles were spin-coated onto an ITO anode, and they were evenly coated without agglomeration, producing a layer having a low surface roughness. Because of the low surface roughness, the scattering transmittance was not noticeably different from the normal direction transmittance, and this suggests that the scattering from the nanoparticles was not a main effect in this study. A microcavity simulation was carried out using MATLAB and it was used to analyze the device. The electroluminescence spectrum enhancement ratio from a simulation and experiments showed a similar tendency, reflecting the microcavity effect that occured from the TiO2 nanoparticles. Enhanced current efficiency, external quantum efficiency, and power efficiency were observed from the OLED device incorporating TiO2 nanoparticles. The electrical characteristics were not changed with optimized density of the TiO2 nanoparticles and the pixels were clear. This indicates that the additional fabrication step of incorporating TiO2 nanoparticles in the OLED enhances the optical efficiency. Furthermore, this method has advantages including easy fabrication by use of a spin-coating process and low cost by the use of TiO2 nanoparticles.
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