EPR and TEM Characterization of Electroluminescent Alq3
EPR and TEM investigations on sublimated solid Alq3, [tris(8- hydroxyquinoline)aluminum(III)] are reported. Different paramagnetic centers in microcrystalline Alq3 fractions as synthesized and annealed are observed. Their nature, thermal treatment dependence, as well as correlation with the crystal structure are analyzed. The existence of randomly oriented triplets and quartets in annealed Alq3 fractions is evidenced from the temperature dependence of X- and Q-band EPR spectra. The spin Hamiltonian parameters are given and proposals for the model structures are made.
Paula Maria Vilarinho
M. N. Grecu et al., "EPR and TEM Characterization of Electroluminescent Alq3 ", Materials Science Forum, Vols. 514-516, pp. 133-137, 2006