We have showed that the doping of an organic salt into a PVK-based polymer emissive layer could enhance the carrier balance greatly to result in higher luminance and luminous efficiency. It is found out that the salt-doped devices show the similar operating characteristics of frozen-junction light-emitting electrochemical cells (LECs). With the salt doping of 0.6 wt.% and an appropriate salt activation process, the fabricated PVK-based polymer light-emitting diodes (PLEDs) shows the luminous efficiency of 15 cd/A at the highest luminance of 55,000 cd/m2 even without an electron-injecting LiF layer. Due to the enhanced carrier balance, the luminous efficiency is found to be maintained from the turn-on voltage to the voltage for the maximum luminance, which means a linear relationship between luminance and current density.
Bibliographical noteFunding Information:
This work was supported by a grant from Gyeonggi Province through the GRRC (Gyeonggi Regional Research Center) program in Sungkyunkwan University.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Materials Chemistry
- Electrical and Electronic Engineering