Surface Raman spectroscopy in ultrahigh vacuum is used to interrogate interfaces formed between tris-(8-hydroxyquinoline) aluminum (Alq3) and vapor-deposited Mg. The Raman spectral results for deposition of Mg mass thicknesses between 5 and 20 Å indicate formation of a complex interfacial region composed primarily of Mg-Alq3 adducts and small-grained amorphous or nanocrystalline graphite, the presence of which may have a significant effect on the electronic properties of this metal-organic interface. The observed shifts in νring, ν(C-N), ν(Al-N), and ν(Al-O) modes along with the appearance of ν(Mg-C) and ν(Mg-O) modes suggest a structure for the Mg-Alq3 adduct in which Mg is bound to the O and C atoms of Alq3. In addition, several intense, broad modes are observed that are consistent with partial graphitization of the Alq 3 film.
ASJC Scopus subject areas
- Colloid and Surface Chemistry