Photoluminescence and characteristics of terbium-doped AlN film prepared by magnetron sputtering

Tb-doped AlN films are prepared by reactive radio frequency (RF) magnetron sputtering under different work conditions. As the RF power increases from 50 to 250 W, the prepared film changes from amorphous to c-axis oriented crystalline. Lower work pressure and higher RF power enhance the deposition rate and crystallinity. The emission from 5D4 to 7FJ (J = 6-0) of Tb3+ are observed on all the films. The intensity of PL spectra of crystalline films is obviously stronger than that of the amorphous films. The PL intensity of 5D4 to 7F6 is the strongest for crystalline film, but for amorphous film that of 5D4 to 7F5 is the strongest. Time-resolved spectra show that there exist two decay time for 5D4 to 7FJ (J = 6, 5): one is shorter ranging from 41 to 60 μs, the other is longer ranging from 202 to 287 μs. The decay time of amorphous film is slightly longer than that of crystalline films.