Exploration of photophysical behavior of RE(TTA)3 dpphen molecular complexes doped in PMMA and PS matrices

This paper put forward the synthesis and photophysical characterization of hybrid organic rare earth complexes namely RE(TTA)3dpphen(RE=Eu/Eu0.5Sm0.5/Sm; Eu: Europim, Sm: Samarium, TTA: 2-Thenoyltrifluoroacetone, dpphen: 4, 7- diphenyl, 1, 10-phennathroline) doped in polymethylmethacrelate (PMMA) and polysterene (PS) at different weight percentage. Photoluminescence (PL) spectra of RE(TTA)3dpphen blended films in PMMA and PS portrayed strong emission in the orange/orange-red region of visible spectrum. The absorption spectra of solvated matrices show two peaks corresponding to π→π* (in the range of 240–275 nm) and n→π* (in the range of 370–390 nm) optical transitions in the range of and respectively. Bathochromic (red) shift in the peak position was observed in solvated films in formic acid as compared to that in dichloromethane. The energy band gap of the films solvated in dichloromethane and formic acid was found to be in the range of 3.16–3.20 eV. PL spectra of the solvated films in dichloromethane showed emission in the red region of visible spectrum while the emission is in blue region for the films solvated in formic acid. CIE diagram of the blended films in solid state and solid state proves the potential of the synthesized complexes as strong contenders with novel feature of tunable emission with the change in media from basic to acidic. These investigations portrayed the potential of blended films as a emissive medium for OLEDs and flat panel displays and solid state lighting.