Photochemical production of electroluminescent image

A polymer containing donorN-epoxypropylcarbazolyl groups and the acceptor tris(8-quinolinolato) aluminum (Alq₃) was shown to form a light-sensitive, acid-producing polymeric composition. The acid in the presence of 8-quinolinol (8-hydroxyquinoline) ensured photochemical dissolution of aluminum in the polyeric layer, yielding additionally organic aluminum complexes, such as Alq₃, Alq²⁺, and Alq ₂ ⁺ , and Alq₃-con-taining polymers. This led to a emergence of electroluminescence (EL) upon application of a potential difference to a sandwich diode representing transparent anode/exposed polymer layer/aluminum cathode. Electroluminescence did not appear at an Alq₃ concentration of 6 wt % and less in the composition, and only partial dissolution of the aluminum film after its deposition on the exposed polymeric layer provided the emergence of EL whose intensity increased with increasing the dose absorbed by the polymer. The addition of the chemical sensitizer dimethylaminobenzaldehyde to the composition triggered the conventional process of chemical amplification which consists in thermal buildup of the acid in exposed area. This provided a significant increase in concentration of organoaluminum complexes and enhancement of EL intensity.