An azomethin-zinc complex for organic electroluminescence: Crystal structure, thermal stability and optoelectronic properties

摘要

An azomethin-zinc complex, bis[salicylidene(4-dimethylamino)aniline]zinc(II) (Zn(sada)(2)) was synthesized and structurally characterized by single-crystal X-ray crystallography. Crystal data for Zn(C15H15N2O)(2) was determined as follows: space group, triclinic, P (l) over bar; a = 10.2791(9) angstrom, b = 16.5008(14) angstrom, c = 17.5984(15) angstrom, alpha = 114.830(2)degrees, beta = 96.579(2)degrees, gamma = 97.674(2)degrees, Z = 4. Through thermal analysis characterization and FT-IR spectra, this complex was proved to have good thermal stability. The vapor-deposited films exhibited uniform and environment-stable morphology. The light emission and charge transporting performance of Zn(sada)2 in organic light emitting diodes (OLEDs) were investigated preliminarily, and the results indicated the superior electron transporting property of this complex. Compared with the typical bilayer device of NN'-diphenyl-N,N'-bis(1-naptithyl)-benzidine (NPB)/tris-(8-hydroxyquinoline)aluminum (Alq(3)), the device with Zn(sada)(2) as the electron transporting layer exhibited a much lower turn-on voltage of 2.5 V (it is usually 3.5 V for an NPB/Alq(3) device). (c) 2005 Elsevier B.V. All rights reserved.