Highly Efficient Three Wavelength WOLEDs by Controlling of Electron-Transfer

Abstract

By controlling the number ofelectrons transferred to the emitting layer, highly efficient three-wavelength WOLEDs were fabricated Such WOLEDs are different from those made using simple stacking of RGB emitting layers ill that the movement distribution ofelectrons transferred to emitting layer could be adjusted using the difference in LUMO energy level and that lights of all 3 wavelengths could be emitted through appropriate arrangement of RGB emitting layers WOLED device with the structure of m-MTDTA(40 nm)NPB (10 nm)/Coumarin6 doped Alq(3)(3%) (8 nm)/ Rubrene (loped NPB (5%) (15 nm)/NPB (2 nm)/ DPVBi (20 nm)/Alq(3) (20 nm)/LiF (1 nm)/Al (200 nm) showed high luminance efficiency of 8 9 cd/A and color purity of(0.31, 0.40). In addition, WOLED device with the thickness of non-doped NPB layer increased from 2 nm to 3nm to increase blue light emission showed a luminance efficiency of 76 cd/A and color purity of(0.28, 0.36).