F. Papadimitrakopoulos et al., CHEMICAL AND MORPHOLOGICAL STABILITY OF ALUMINUM TRIS(8-HYDROXYQUINOLINE) (ALQ(3)) - EFFECTS IN LIGHT-EMITTING DEVICES, IEEE journal of selected topics in quantum electronics, 4(1), 1998, pp. 49-57
Aluminum tris(8-hydroxyquinoline) (Alq(3)) is presently considered one
of the most reliable electron transporting and emitting materials for
molecular-based organic light-emitting diodes (OLED's), This paper su
mmarizes the investigations that our group, over the past three years,
have conducted into the physical and chemical response of Alq(3) in t
he presence of small amounts of moisture. The characteristic evolution
of 8-hydroxyquinoline (8-Hq), a volatile byproduct of the hydrolysis
of Alq(3), was quantified using thermogravimetric and gas chromatograp
hy/mass spectroscopy (GC/MS) analysis as a function of sample morpholo
gy, Annealed (more crystalline) samples exhibited greater stability to
hydrolysis than freshly sublimed films, at the expense of photolumine
scence (PL) efficiency, These phenomena are discussed with respect to
failure mechanisms observed in Alq(3)-based OLED's.