Preparation of Er, Eu, and Ce Co-doped Ta2O5 Thin Films Using a Simple Co-sputtering Method

Many studies on rare-earth-doped tantalum (V) oxide (Ta2O5) have been conducted because Ta2O5 is a potential host material for new phosphors due to its low phonon energy (100–450 cm−1) compared with other oxide materials such as SiO2 [1]. We have reported on various rare-earth (Er, Eu, Tm, and Y) doping into Ta2O5 thin films using simply co-sputtering of rare-earth oxide (Er2O3, Eu2O3, Tm2O3, and Y2O3) pellets and a Ta2O5 disc [2-5]. Moreover, yellow light emission from gallium nitride (GaN) co-doped with Er and Eu was reported [6], and the sensitization of photoluminescence (PL) from rare-earth ions by cerium (Ce) was demonstrated [7]. In this study, we fabricated Er, Eu, and Ce co-doped Ta2O5 (Ta2O5:Er, Eu, Ce) thin films using the same co-sputtering method for the first time, and observed yellow PL from a Ta2O5:Er, Eu, Ce film.