Abstract
Pink light emission from the Al electrode has been observed during AC anodizing at 10∼60Hz, 50∼65V of Al in aqueous solutions containing Eu3+ ion.
The emission peaks at 590, 612, 653, 703nm were assigned respectively to the 5D0-7F1, 5D0-7F2, 5D0-7F3 and 5D0-7F4 transitions of the Eu3+ activator, and appeared only during cathodic half periods.
It is concluded that the pink emission is electroluminescence caused by the excitation of cathodically injected Eu3+ accompanying hydrogen evolution due to the electrolytic rectification into the thin barrier Al2O3 layer to which high electric field was applied.
