Bluish-Green Light Emitting Zinc Complex for OLED Application

Zinc (II) was complexed with 8-hydroxyquinoline-5-sulphonic acid (L) to give an ZnL

2

complex (1:2 molar ratio). The synthesized complex was characterized by infrared spectra, differential thermal analysis and thermogravimetry. The UV-absorption and photoluminescence (PL) spectra show peaks at 377 nm and 502 nm respectively. The OLED device has been fabricated by depositing the thin films of different materials on ITO, hole transport layer was obtained by depositing a thin film of 4,4-bis[

N

-(1-naphthyl)-

N

-phenyl-amino]biphenyl (α-NPD), Bis(8-hydroxyquinolinato-5-sulphonic acid)zinc(ZnL

2

) as emissive layer, BCP as hole blocking layer, thin film of Alq

3

as electron transport layer and LiF/Al as electron injecting electrode. The EL device was characterized for electroluminescence and the peak was reported at 503 nm. The EL spectrum of complexes ZnL

2

is found that there is a considerable blue shift in the EL spectra from its un-substituted counter complex when electron-withdrawing group is introduced at 5th position in quinoline ring.