Luminescence properties of novel deep‐red‐emitting Ca3Al2Ge2O10:Cr3+ phosphors

Ca3Al2Ge2O10:Cr3+ phosphors were prepared by a high‐temperature solid‐state method, and their luminescence properties were investigated. Under excitation at 550 nm, Ca3Al2Ge2O10:Cr3+ phosphors exhibited a broad red emission band at 697 nm in the range 650–750 nm that was caused by the 2E→4A2 transition of Cr3+. For the 697 nm emission peak, emission intensity reached a maximum at x = 0.07, and there was concentration quenching of Cr3+ in Ca3Al2Ge2O10; the corresponding concentration quenching mechanism was analysed. Under excitation at 262 nm, the Ca3Al2Ge2O10:Cr3+ phosphor showed a weakly broad emission band in the range 350–600 nm that was caused by intrinsic defects (V′′Ca and V′′O).