BaAl₂S₄:Eu thin films sputtered by complex target with spark plasma sintering BaS:Eu pellets

Europium doping barium thioaluminates thin films are sputtered by Al complex target embedded with BaS:Eu pellets sintered by spark plasma sintering (SPS). Thin films are deposited by RF-sputtering with complex target. BaAl ₂S₄: is found in each thin film sample while BaAl ₄S₇ appears in the samples only if the amount of BaS:Eu pellets is more than 3. Oxidizing products are BaAl₂O₄, BaSO₄ and Al₂O₃. The amounts of barium thioaluminates including BaAl₂S₄: and BaAl ₄S₇ will increase while the one of Al₂O ₃ and BaS decrease if more BaS:Eu pellets are embedded in the target during sputtering. Elements analysis is carried out by EDS. The Al/Ba ratio in thin films will approach 2.0 with more pellets existing in target. PL spectra of thin films are measured and analyzed. The most obvious emission peak in each spectrum is located at about 470nm which corresponds to the 4f ⁶5d¹→4f⁷ transition of Eu₂₊ in BaAl₂S₄: lattice. The emission peak will approach 470nm as more pellets are embedded in complex target. As a result, it can be concluded that increasing the amounts of BaS:Eu pellets in complex target is an efficient way to achieve better Eu doping barium thioaluminates thin film.