Characterization and photoluminescence of AlN:Eu films

Two serials of Eu3+ doped AlN films are prepared by means of magnetron RF reactive sputtering under different RF powers and N2/(N2 + Ar) ratios. XRD analysis indicates that the films change from amorphous to c-axis oriented crystalline as the RF power increases or as the N2/(N2 + Ar) ratio decreases. Lower N2/(N2 + Ar) ratio and higher RF power enhance the deposition rate and crystallinity. The grain size and surface roughness observed by SEM and AFM increase with the increase of the RF power. The emission from 5D0 to 7FJ (J = 0-4) of Eu3+ is observed in the PL spectra for all the crystalline films, and the 5D0 to 7F2 transition of the films grown at 300 W has double exponential decays, 38 and 161 μs. The crystalline quality of the films improves the photoluminescence intensity.