Synthesis and EL properties of aluminum and α-pyridoin complex

A novel light emitting aluminum complex containing the dihydroxy derivative of trans-1,2-dipyridylethene (PAl), α-pyridoin, was synthesized and its electroluminescent (EL) properties were characterized. The structure of complex PAl was elucidated by FT-IR, solid state 1H-NMR, UV-Vis and XPS. The complex PAl showed thermal stability up to 350 °C under nitrogen flow, which was measured by TGA and DSC. The photoluminescence (PL) was measured from the PAl film on quartz substrate. The PL emission exhibited green light centered at about 490 nm. Electroluminescent (EL) devices were fabricated by the vacuum deposition. The EL devices having the structure of ITO/TPD/PAl/Al were studied, where N,N-bis(3-methylphenyl)-N,N′-diphenylbenzidine (TPD) was used as a hole transporting layer. TPD hole transport layer was 40 nm thick and PAl emitting layer 60 nm thick. The PAL device showed yellow emission at 575 nm. The maximum brightness of 91 cd/m2 was observed from the PAl EL device.