Materials Chemistry and Physics, Vol.136, No.1, 173-178, 2012
Effect of ionic liquids on the electroluminescence of yellowish-green light-emitting electrochemical cells using bis(2-(2,4-difluorophenyl)pyridine)4,7-diphenyl-1,10-phenanthroline-irid ium(III) hexafluorophosphate
A cationic iridium complex [Ir(dfppy)(2)(dpphen)]PF6, where dfppy is 2-(2,4-difluorophenyl)pyridine, dpphen is 4,7-diphenyl-1,10-phenanthroline and PF (6) over bar is hexafluorophosphate, has been synthesized and its photophysical and electrochemical properties were investigated. Light-emitting electrochemical cells (LECs) based on this complex were fabricated using air stable electrodes and emits yellowish-green light (533 nm) with Commission Internationale de L'Eclairage (CIE) coordinates of (0.35, 0.59) at 4 V. Effect of two different imidazolium based ionic liquids (ILs) viz, 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF6) and 1-ethyl-3-methylimidazolium hexafluorophosphate (EMIMPF6) on the active layer has been studied and the luminance and the current density of the devices were found to be enhanced with increasing ionic conductivities. (c) 2012 Elsevier B.V. All rights reserved.