Ka. Higginson et al., THERMAL AND MORPHOLOGICAL EFFECTS ON THE HYDROLYTIC STABILITY OF ALUMINUM TRIS(8-HYDROXYQUINOLINE) (ALQ(3)), Chemistry of materials, 10(4), 1998, pp. 1017-1020
An investigation into the physical and chemical characteristics of alu
minum tris(8-hydroxyquinoline) (Alq(3)), a reliable electron-transport
ing and emitting material for low molecular weight based organic light
-emitting diodes (OLEDs), was performed. In the presence of atmospheri
c moisture, the thermal stability of Alq(3) was studied by monitoring
the evolution of its volatile byproduct, 8-hydroxyquinoline (8-Hq), us
ing thermogravimetric analysis and gas chromatography/mass spectroscop
y (GC/MS). Sample morphology was shown to be an important parameter in
the stability of Alq(3). Annealed (more crystalline) samples exhibite
d greater stability to hydrolysis than freshly sublimed films, at the
expense of photoluminescence efficiency. The possible implications of
these phenomena are discussed with respect to failure mechanisms of Al
q(3)-based OLEDs.