Investigations on RE(TTA)3tppo (RE = Eu/Sm/Eu0.5 Sm0.5) rare earth β-diketonate complexes for OLEDs and solid state lighting

Abstract

Rare earth hybrid organic β-diketonate complexes of Eu(III), TTA and tppo; Eu(TTA)3tppo, Sm(TTA)3tppo and Eu0.5Sm0.5(TTA)3tppo [Eu: europium, Sm: samarium, TTA: Thenoyl Trifluoro Acetone, tppo: Triphenylphosphine oxide] were synthesized by solution technique, maintaining pH 7. X-ray diffractogram of all the complexes revealed their crystalline nature. TGA curves infer their thermal stability to be in the range of 230–260 °C. The optical energy band gap of these complexes was found to be in the range of 3.08–3.20 eV. When RE(TTA)3tppo complexes were excited at 377 nm, 382 nm and 382 nm respectively, the emission spectra portrays red emission, peaking at 616 nm, 645 nm and 616 nm in solid state, while in solvated state, hypsochromic shift (shift toward lower wavelength) was noticed. CIE co-ordinates and color correlated temperature (CCT) of the complexes tuned according to their emission wavelength. These investigations provide a good deal of information regarding their suitability for the fabrication of red to blue tunable light emitting organic light emitting diodes (OLEDs), panel displays and solid state lighting panels on flexible substrates.

Keywords

• Rare earth β-diketonates
• Europium
• Samarium
• OLED devices
• Flat panel displays
• Solid state lighting