n-Type ternary zinc complexes: Synthesis, physicochemical properties and organic light emitting diodes application

作者：Kumar Amit; Palai Akshaya K; Srivastava Ritu^*; Kadyan Pratap S; Kama****nan Modeeparampil N; Singh Ishwar

来源：Journal of Organometallic Chemistry, 2014, 756: 38-46.

DOI：10.1016/j.jorganchem.2014.01.022

• Zinc complex
• Fluorescence lifetime
• Transient electroluminescence
• Electron transport material

We report synthesis, characterization and use of ternary zinc complexes as emissive and electron transport material in organic light emitting devices (OLED). 5,7-Dimethyl-8-hydroxyquinoline or 2-carbonitrile-8-hydroxyquinoline have been used with 2-(2-hydroxyphenyl)benzoxazole to synthesize (2-(2-hydroxyphenyl)benzoxazolato) (5,7-dimethyl-8-hydroxyquinolinato)zinc(II) [Zn(HPB)(Me(2)q)] and (2-(2-hydroxyphenyl) benzoxazolato)(2-carbonitrile-8-hydroxyquinolinato)zinc(II) [Zn(HPB)(CNq)] complexes. These complexes possessed high thermal stability and having good film forming property. Optical properties of the synthesized complexes have been studied by UV-visible absorption, photoluminescence and time resolved photo-luminescence spectroscopy. Density functional theoretical calculations have been performed to demonstrate the three-dimensional geometries and the frontier molecular orbital energy levels of these compounds. Synthesized materials show quite good efficiency in multilayered device structure ITO/alpha-NPD/Zinc complex/BCP/Alq(3)/LiF/Al with maximum brightness of 7017 cd/m(2) and 6925 cd/m(2) having electroluminescence spectral peak emission centered at 567 nm and 569 nm, respectively. Electron mobility of these molecules were found to be 1.5 x 10(-6)-1.2 x 10(-5) cm(2)/V s for electric field range 1000-1200 (V/cm)(1/2) and hence showed very high efficiency as electron transport layer in device structure ITO/alpha-NPD/5% Ir(ppy)(3) doped CBP/BCP/Zn(HPB)(Me(2)q) or Zn(HPB)(CNq)/LiF/Al.

• 出版日期2014-4-15