Electroluminescent characteristics of bis(5-chloro-8-hydroxyquinolinato)- zinc(II) complex

Abstract

A zinc(II) complex with 5-chloro-8-hydroxyquinoline has been used as emitting material to produce yellow light. On excitation by UV light at 385 nm, thin film of the complex fluoresced at 550 nm. Multilayer organic electroluminescence devices fabricated using this fluorescent material produce emission with good chromaticity (CIE coordinates <i>x</i> = 0.313 and <i>y </i>= 0.576). Maximum luminance of 466 cd/m² is achieved when 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane is used as dopant in 4,4-bis[N-(1-naphthyl)-N-phenyl-amino]biphenyl at 12 V. The devices show typical non-linear diode current-voltage characteristics under forward bias with the threshold voltage of 6V. The CIE coordinates are found to be independent of the operating voltage.