Near-field fluorescence microscopy of tris-8-hydroxyquinoline aluminum films

The dependence of the nanoscale optical properties of Alq(3) on film morpho logy (Alq(3) = tris-8-hydroxyquinoline aluminum) is still poorly understood , although Alq(3) is widely used as the emissive layer in organic LEDs. Her e near-field scanning optical microscopy (NSOM) is used to probe the local optical and morphological properties of Alq(3) films. It is shown that feat ures as small as 10-100 nm cain be observed, a resolution not obtained with previously used techniques. Differences in the quality of vacuum-deposited , spin-cast, and drop-cast films are investigated using this technique.