Blue Electroluminescence in Thin Films of Azomethin-Zinc Complexes

Abstract

Organic electroluminescent (EL) cells with azomethin-zinc complexes as an emitting layer showed bright blue emission. A cell structure of [indium-tin-oxide (ITO)/hole transport layer/emitting layer/MgIn] was employed. The color was blue, and emission peaks were 458∼470 nm. High luminance exceeding 1000 cd/m2 was obtained for the first time with an EL cell using a complex emitting material. The azomethin-zinc complexes exhibited good electron transport, as indicated by the high luminance obtained in two-layer EL cells.

Isomerism and Blue Electroluminescence of a Novel Organoboron Compound: BIII2(O)(7-azain)2Ph2

“…This is justified insofar as physical properties, such as sublimation enthalpy and solubility, that are related to the solid state display a similar alternation whereas the properties of the liquid phase have a monotonic dependency on increasing chain length. [3] For the n-alkanes with n 6 ± 24 (n number of C atoms) the even numbered members crystallize at low temperatures in a triclinic space group, while for n 26 monoclinic packing is observed. It is possible to define an orthorhombic sub-cell for the latter, [3a] which is also found as the real cell for polyethylene [4] and mixed paraffins.…”

“…Previously reported blue emitters of organometallic or coordination compounds in organic EL devices employed either derivatives of 8-hydroxyquinoline or azomethine as the emitting ligands. [3,4] The common feature of those previously reported blue emitting ligands is that they are all chelating ligands and bind to the central atom through both nitrogen and oxygen donor atoms. We have been interested in the application of organometallic and coordination compounds in EL devices because the properties of this class of compounds such as volatility and stability can be modified readily by manipulating the coordination environment around the central atom.…”

“…7 reported blue emitting ligands. Furthermore, the commonly used central ions in previously known organometallic or coordination blue emitters [3,4] are Al III , Zn II , and Be II . Blue emitters using boron as the central atom are previously unknown, although a few blue photoluminescent boroncontaining polymers and small molecules and electron-transporting organoboron compounds have been reported recently.…”

Synthesis, structure, optoelectronic properties of novel zinc Schiff-base complexes

“…Zinc(II) schiff-base chelates are well-known for their high photoluminescence efficiencies, and had been used as blue electroluminescent materials as early as in 1993 [24]. From then on, many efforts have been devoted to the development of novel electroluminescent zinc (II) Schiff-base complexes [2527].…”

A New Class of Blue-Emitting Materials Based on 1,3,5-Oxadiazole Metal Chelate Compounds for Electroluminescent Devices

“…This class of compounds generally offers many attractive properties such as displaying a double role of electron transport and light emission, high thermal stability, and ease of sublimation. The major drawback of metal±chelate compounds, however, is the lack of suitable blue-emitting molecules.Only a few types of blue-emitting metal±chelate compounds, such as metal complexes based on 2-methylquinolin-8-ol, [4] azomethine, [5] and 7-azaindole, [6] have been previously reported. In this communication, we present a new class of blue-emitting compounds for EL applications based on oxadiazole ligands.…”