X-ray excited luminescence of SrAl2O4:Eu,Dy at low temperatures

- An addition to the mechanism of long lasting phosphorescence in SrAl2O4: Eu, Dy is proposed.
- Eu2+ and Dy3+ serve as hole traps and the Eu3+ as well as Dy4+ are accumulated.
- At 10 K excited Eu2+ and Dy3+ centers are created via electron tunneling from host trap to Eu3+ and Dy4+ ions.