Electrochemiluminescence on Dy(III) and Tb(III)-doped Al/Al2O3 surface electrode

The electrochemiluminescence (ECL) of aqueous electrolyte solutions containing EDDHA and an oxide-covered aluminum electrode doped with Dy(III) or Tb(III) during the cathodic pulse-polarisation was investigated. Injection of tunnel-emitted hot electrons from the electrode into complexes of solutions containing S2O82-, induces ECL, as observed in the 5D4 → 7FJ transitions in Tb(III) and 4F9/2 → 6H15/2 and 4F9/2 → 6H13/2 in Dy(III) ions. Specific electrogenerated luminescence was obtained by producing highly oxidizing and reducing species as: hydrated electrons, hydroxyl and sulfate radicals. These strong red-ox reactants efficiently excite the complexed Tb(III) and Dy(III) ions by ligand → metal energy transfer.