Preparation of M2B5O9Cl:Eu2+ (M=Sr, Ca) blue phosphors by a facile low-temperature self-reduction method and their enhanced luminescent properties

In this work, through a facile method of low-temperature (only 350 °C) self-reduction, 1D nano-sized M 2 B 5 O 9 Cl:Eu 2+ (M = Sr, Ca) blue phosphors with highly efficient performance can be obtained. The crystal structure, morphology and photoluminescence (PL) properties including thermal stability of M 2 B 5 O 9 Cl:Eu 2+ (M = Sr, Ca) phosphors were investigated. The M 2 B 5 O 9 Cl:Eu 2+ (M = Sr, Ca) phosphors show broad band excitation spectra and narrow band emission spectra . The photoluminescence quantum yields (PLQY) of M 2 B 5 O 9 Cl:Eu 2+ (M = Sr, Ca) are as high as 98% and 87.2%, respectively. Furthermore, the color purities of M 2 B 5 O 9 Cl:Eu 2+ (M = Sr, Ca) can reach 99.1% and 93.2%, respectively. When heated up to 150 °C, the emission intensities of M 2 B 5 O 9 Cl:Eu 2+ (M = Sr, Ca) phosphors can still keep 72.7% and 80.0%, respectively. Finally, the above-mentioned phosphors exhibit outstanding performance when manufacturing WLEDs.