Raman and X-ray photoelectron spectroscopic investigation of solution processed Alq₃/ZnO hybrid thin films

In this study, we characterize the solution processed tris-(8-hydroxyquinoline)aluminum(Alq₃)/ZnO hybrid thin films using Raman and X-ray photoelectron spectroscopic (XPS) techniques. Raman studies reveal the sol-gel derived spin-coated ZnO thin film has hexagonal wurtzite structure. The incorporation of Alq₃ molecules in the hybrid film results in the formation of bonding onto the surface of highly crystalline ZnO nanoparticles. The XPS confirms the incorporation of Alq₃ in the hybrid thin films and corroborates that the Alq₃ molecules may be adsorbed onto the surface of ZnO nanoparticles (chemisorption), showing the existence of chemical interaction between Alq₃ and ZnO in the hybrid films. These studies support that the chemisorbed Alq₃ molecules onto the ZnO nanoparticles may facilitate the charge transfer (non-radiative) between Alq₃ and ZnO in the hybrid thin films which will be useful to enhance the optical and electrical properties for the optoelectronic device applications.