Concentration quenching behavior of Stokes and upconversion luminescence for Pr3+-doped Y3Al5O12

In Pr 3+ -doped Y 3 Al 5 O 12 , the blue-to-UV upconversion luminescence is significantly more affected by concentration quenching than the UV Stokes luminescence, which is due to cross-relaxation involving the upconversion intermediate states 3 P J and 1 D 2 .