Effect of reducing and oxidizing atmosphere on photoluminescence of undoped and Eu doped nanostructured CaAl2O4

Bluish-green afterglow and blue photoluminescence of undoped BaAl2O4

“…Oxygen and barium vacancies are well known to be the most common defects in BaAl 2 O 4 . After considering the oxygen vacancy and cation vacancy related emissions in SrAl 2 O 4 , 19,24–26 CaAl 2 O 4 , 20–22,46 BaAl 2 O 4 , 7 SrSO 4 , 29,51 HfO 2 , 52 ZnWO 4 , 53 and ZnMoO 4 , 54,55 we tend to hold the oxygen and barium vacancies in BaAl 2 O 4 liable for the two PL bands in Fig. 6(b).…”

“…6(a) after scaled by a factor of hc / E 2 . 45,46 The scale factor is responsible for the difference in the PL intensities of Fig. 6(a) and (b).…”

“…6(a) is converted into a PL spectrum in energy scale by employing the Jacobian transformation. 45,46 Fig. 6(b) depicts the resultant PL spectrum in energy scale, which can be deconvoluted into one green PL band peaking at 2.53 eV (490.1 nm) and one blue PL band centering at 3.08 eV (402.6 nm).…”