| 초록 |
Top emitting organic light emitting diodes (TOLEDs) can be fabricated on opaque substrates such as silicon, flexible metal foil, or active matrix substrates with lower aperture ratio. However, the light extraction issue of TOLED has not been actively investigated due to the strong microcavity effects. Here, the three-dimensional corrugated patterns by the spontaneous process were formed on top of the translucent cathode of TOLEDs. These patterns of the thermally deposited organic bilayer were formed by the mismatch of thermal expansion coefficient. The pitch and depth of patterns can be systematically controlled, depending on the annealing temperature and time. Luminous efficiency of device with patterns was significantly increased without change of the spectral characteristics and color stability. Such a result can be explained by the suppression of light loss due to the surface plasmon polariton mode at metal/air interface by the buckling structure. |
