Manipulation of recombination zone by utilizing the donor of electroplex as a spacer
Abstract
The emission of electroplex is varied with applied voltages, leading to poor color stability of devices. In this work, the recombination region was investigated in organic light-emitting diodes (OLEDs) based on the electroplex between N,N'-diphenyl-N,N'-bis(1-naphthyl-phenyl)-1,1‧-biphenyl-4,4‧-diamine(NPB) and 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,2,4-oxadiazole (PBD). Color stability was manipulated by introducing the donor of electroplex as a spacer, which plays an important role of recombination zone for electroplex-based OLEDs. The 5-nm-spacer-device brought out a tolerable chromaticity coordinate shift of less than 0.01 for both x- and y-value. White light emission with CIE coordinates of (0.37,0.28) and (0.33,0.26) at 12V was achieved when the thickness of spacer was 7 and 10nm, respectively. The 7-nm-spacer-device exhibited better color stability than the 10-nm-spacer-device. This proves that adjusting spacer thickness is a simple and efficient method to control recombination region and can be useful for fulfilling color-stable electroplex-based white emission.
- Publication:
-
Journal of Luminescence
- Pub Date:
- November 2016
- DOI:
- 10.1016/j.jlumin.2016.07.032
- Bibcode:
- 2016JLum..179..469L
- Keywords:
-
- Electroplex;
- Color stability;
- Spacer;
- CIE coordinate;
- Recombination region