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

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 x = 0.313 and y = 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

Synthesis and characterization of 5,7-dimethyl-8-hydroxyquinoline and 2-(2-pyridyl)benzimidazole complexes of zinc(II) for optoelectronic application

Bis(5,7-dimethyl-8-hydroxyquinolinato)zinc(II) (Me2q)2Zn and 5,7-dimethyl-8-hydroxyquinolinato(2-(2-pyridyl)benzimidazole) zinc(II) Me2q(pbi)Zn have been synthesized and characterized by various techniques. These metal complexes have high thermal stability (>300 °C) and high glass transition temperatures (>150 °C). The vacuum deposited films of these materials show good film forming property and are suitable for opto-electronic applications. Multilayered organic electroluminescent (EL) devices have been fabricated having structure ITO/α-NPD/zinc complex/BCP/Alq3/LiF/Al, which produce emission with chromaticity having Commission Internationale d’Eclairage (CIE) coordinates x = 0.506 and y = 0.484 for (Me2q)2Zn; x = 0.47 and y = 0.52 for (Me2q)(pbi)Zn complex. The electroluminescence spectra show peak emission centered at 572 and 561 nm respectively for these materials

Synthesis, Characterization, and Electroluminescent Characteristics of Mixed-Ligand Zinc(II) Complexes

Mixed-ligand zinc complexes, i.e., 2-(2-hydroxyphenyl)benzothiazolato-5,7- dichloro-8-hydroxyquinolinato zinc(II) [ZnBTZ(Cl(2)q)], 2-(2-hydroxyphenyl) benzothiazolato-5,7-dimethyl-8-hydroxyquinolinato zinc(II) [ZnBTZ(Me(2)q)], and 2-(2-hydroxyphenyl)benzothiazolato-2-carbonitril-8-hydroxyquinolinato zinc(II) [ZnBTZ(CNq)], were synthesized and characterized. The metal complexes have high thermal stability (> 300A degrees C) and high glass-transition temperature (> 150A degrees C) and are suitable for optoelectronic applications. Optical properties of the synthesized complexes were characterized by using ultraviolet-visible (UV-Vis) and photoluminescence spectroscopy. Color tuning by changing the ligand was observed in synthesized complexes. Multilayered organic electroluminescent devices were fabricated having structure indium-tin oxide (ITO)/N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4'-diamine (alpha-NPD)/zinc complex/2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP)/tris(quinolinolate)Al-III (Alq(3))/LiF/Al using the synthesized complexes as emissive material. The electroluminescence spectra show peak emission centered at 532 nm, 572 nm, and 541 nm, respectively, for these materials. The emitted light has chromaticity with Commission Internationale d'A parts per thousand clairage coordinates x = 0.35 and y = 0.56 for ZnBTZ(Cl(2)q), x = 0.49 and y = 0.47 for ZnBTZ(Me(2)q), and x = 0.48 and y = 0.40 for ZnBTZ(CNq) complex