Synthesis and optical properties of ZnO incorporated Tris-(8-hydroxyquinoline)aluminum

Tris-(8-hydroxyquionoline)aluminum(Alq3) and different weight percentages (2 wt%, 5 wt%, 10 wt%, 20 wt%, 30 wt%, 40  wt% and 50 wt%) of ZnO incorporated hybrid Tris-(8-hydroxyquinoline)aluminum (Alq3/ZnO) composite were synthesized by a low cost and simple precipitation method under low temperature. XRD patterns reveal that the amorphous nature of pure Alq3 particles transforms into α-phase crystalline for hybrid Alq3/ZnO composite materials. The FTIR spectrum confirms the formation of quinoline with absorption in the region 600-800 cm−1. It also reveals the stretching vibration of Zn-O at 400-500 cm−1 in Alq3/ZnO composite particles. The band gap (HOMO-LUMO) of Alq3 particles was calculated using absorption spectra and it is 2.92 eV. The photoluminescence (PL) spectrum of Alq3 particle exhibits an emission at 507 nm when excited at 390 nm. Alq3/ZnO composite containing 30 wt% of ZnO exhibits maximum luminescence intensity.