Ag+ ion exchange of the Na-beta "-Al2O3 single-crystal film has been achieved in AgNO3 aqueous solution at 80-95 degrees C. Complete exchange was achieved at >90 degrees C. Multi-doped Cu(I)/Na/Ag ions have been successfully patterned in the single crystal films via electrical-field assisted ion exchange. Distinct, different-colour luminescent regions can thus be generated in beta "-Al2O3 single-crystal films.