Photo-, cathodo-, and electroluminescence studies of sputter deposited AlN:Er thin films

Green cathodoluminescence (CL), photoluminescence (PL) and electroluminescence (EL) have been obtained from Er-doped amorphous AlN thin films, 200 nm thick, prepared by rf magnetron sputtering. All films were activated by annealing at 750°C for 10 min in a nitrogen atmosphere. Three sharp bands at about 479, 538 and 559 nm corresponding to the 4F7/2→4I15/2,2H11/2→4I15/2 and 4S3/2→4I15/2 transitions are observed. Fine structure is seen on the major transitions that does not change with temperature indicating that this structure is related to different local environments of the Er3+ ion. The PL spectrum revealed sharp peaks from Er3+ ions and a broad spectral profile that might be from defect states in the amorphous AlN. The results from EL measurements show that Er-doped amorphous AlN films can be used as a phosphor layer in alternating-current thin-film electroluminescent (ACTFEL) devices.