Color-tunable luminescence and temperature sensing properties of Bi3+/Sm3+ or Bi3+/Eu3+ codoped Ba2Gd2Ge4O13 phosphors

A new series of Bi 3+ /Sm 3+ and Bi 3+ /Eu 3+ codoped Ba 2 Gd 2 Ge 4 O 13 phosphors crystallizing in the monoclinic system (S.G. C 2/ c ) have been prepared. The studied germanates are promising materials for non-contact temperature measurements.