Photoluminescence, Optical, and Electrical Properties of Bis(8-Hydroxyquinoline) Zinc and Tris-(8-Hydroxyquinoline) Aluminum Organometallics and Their Films

Bis(8-hydroxyquinoline) zinc (ZnQ(2)) and tris-(8-hydroxyquinoline) aluminum (AlQ(3)) organometallics have been synthesized and incorporated into poly(methyl methacrylate) (PMMA) films for potential use in green-emitting OLED applications. The ZnQ(2) and AlQ(3) organometallics were prepared using an acid-base co-precipitation technique. Fourier-transform infrared spectroscopy and x-ray diffraction patterns were utilized to confirm the formation of ZnQ2, AlQ(3), and ZnQ(2)-AlQ(3) compounds. UV-Vis spectroscopy analysis revealed that PMMA/ZnQ(2), PMMA/AlQ(3), and PMMA/(ZnQ(2)-AlQ(3)) composite solutions exhibited two primary transition bands in the range of approximately 330 nm and 380 nm, corresponding to the pi-pi* and n-pi* transition bands, respectively. The average electrical conductivity of the PMMA/ZnQ(2) composite film was measured as 1.19 mu S/cm, while the PMMA/AlQ(3) composite film displayed a conductivity of 1.56 mu S/cm, indicating that the intra-ligand charge-transfer of electrons in AlQ(3) was higher than that in Znq_2. Additionally, photoluminescence (PL) emission peaks for the PMMA/ZnQ(2), PMMA/AlQ(3), and PMMA/(ZnQ(2)-AlQ(3)) composite solutions were observed at wavelengths of 522 nm, 505 nm, and 509 nm, respectively, confirming their potential suitability for use in green-emitting OLEDs.

Automated summary

Bis(8-hydroxyquinoline) zinc (ZnQ(2)) and tris-(8-hydroxyquinoline) aluminum (AlQ(3)) organometallics have been synthesized and incorporated into poly(methyl methacrylate) (PMMA) films for potential use in green-emitting OLED applications. Various analyses confirm the formation of the compounds, and measurements of conductivity and photoluminescence suggest their suitability for green-emitting OLEDs.