A highly fluorinated iridium complex as a blue-green emitting component for white electroluminescence

Abstract

A novel perfluorinated heteroleptic iridium complex, namely iridium(III)bis[2-(2,5,2′,3′,4′,5′,6′-heptafluoro-biphenyl-4-yl)-pyridinato-N,C2′][3-(pentafluorophenyl)-pyridin-2-yl-1,2,4-triazolate] (Ir-F19), has been synthesized and characterized both in solution and in the solid state. The compound displays blue-green photoluminescence, with emission peaks at 480 and 512 nm and 68% quantum yield, in degassed acetonitrile solution. The use of this phosphor in blue and white organic light emitting devices (WOLEDs) has been investigated. Current efficiency of 8.3 cd/A at 100 cd/m2 has been recorded for the blue emitting device whereas white electroluminescence with good color rendering index (CRI = 76) and CIE coordinates (0.43, 0.42) have been observed for a WOLED made of two stacked layers based on Ir-F19 and the commercial orange Ir(MDQ)2(acac) [bis(2-methyldibenzo[f,h]quinoxaline)(acetylacetonate)iridium(III)]. WOLED luminous efficiency of 10.5 cd/A at 100 cd/m2, almost constant (10.1 cd/A) up to 1000 cd/m2, indicates that Ir-F19 is a promising blue-green emitting component for white electroluminescence