A systematic study has been conducted on microcavity organic light emitting diodes (OLEDs) based on green, red and blue phosphorescent emitters to elucidate the microcavity effects for different color emitters. We found that the luminance output is determined by the reflectivity of the semitransparent electrode and the photopic response of the green, red and blue emitters. While the luminance enhancements of blue and red phosphorescent microcavity devices are small, a current efficiency as high as 224 cd A 21 is obtained in the green phosphorescent microcavity OLEDs.

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QD-OLED device performance is unsatisfactory nowadays, due to the limited efficiency of blue OLED material as well as the low efficient converting rate of QD material. Here we proposed a novel structure of QD-OLED, using white OLED as the excitation. The device shows higher optical efficiency compared with QD-OLED with Blue OLED as excitation. In addition, a 6.6 inch green QD-OLED was demostrated with the proposed structure.

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Defective silica sphere arrays having locally hexagonal-closedpacked structure but lack of long range ordering were incorporated into phosphorescent organic light emitting diode devices as grating to extract the waveguided modes. With a 0.5 μm grating, the current and power efficiency were enhanced by 55% and 110% without spectral changes and directionality.