Luminescence properties of novel deep‐red‐emitting Ca 3 Al 2 Ge 2 O 10 :Cr 3 + phosphors

Ca 3 Al 2 Ge 2 O 10 :Cr 3 + phosphors were prepared by a high‐temperature solid‐state method, and their luminescence properties were investigated. Under excitation at 550 nm, Ca 3 Al 2 Ge 2 O 10 :Cr 3 + phosphors exhibited a broad red emission band at 697 nm in the range 650–750 nm that was caused by the 2 E→ 4 A 2 transition of Cr 3 + . For the 697 nm emission peak, emission intensity reached a maximum at x = 0.07, and there was concentration quenching of Cr 3 + in Ca 3 Al 2 Ge 2 O 10 ; the corresponding concentration quenching mechanism was analysed. Under excitation at 262 nm, the Ca 3 Al 2 Ge 2 O 10 :Cr 3 + phosphor showed a weakly broad emission band in the range 350–600 nm that was caused by intrinsic defects (V′′ Ca and V′′ O ). Copyright © 2016 John Wiley & Sons, Ltd.