Enhanced self-host blue emission of CaSrSb2O7 materials via Bi3+ ion doping for high CRI WLEDs, security inks and flexible displays

Luminescent materials are indispensable in our daily lives and have already been widely applied in various fields. Herein, novel self-host blue-emitting CaSrSb 2 O 7 and CaSrSb 2 O 7 :Bi 3+ phosphors with orthorhombic space group Imma (74) were successfully prepared. The phase purity, elemental composition, morphology, luminescent behaviors, etc. were investigated in detail. To compare the luminescence properties of rare-earth-activated phosphors, the self-host blue-emitting CaSrSb 2 O 7 phosphor with unique performance exhibited a good quantum yield (QY) of 39.81%, and its emission intensity and QY could also be improved by doping Bi 3+ ions. The CaSrSb 2 O 7 :Bi 3+ phosphor was located in the pure blue region with the Commission Internationale de I'Eclairage chromaticity coordinate of (0.151, 0.058) and good color purity of 89.35%. For identifying its potential applications, the packaged white light-emitting diode device emitted a high color rendering index value of 93.66 under a forward current of 300 mA, and it would be further applied in security inks and flexible displays owing to its strong emission by the naked eyes. These results suggest that novel self-host blue-emitting CaSrSb 2 O 7 :Bi 3+ phosphors could be used in multifunctional applications. • Novel self-host blue-emitting CaSrSb 2 O 7 materials were successfully prepared. • The luminescence performances were improved by doping Bi 3+ ions. • The optical characterizations were investigated in detail. • The packaged WLED exhibited a high CRI value of 93.66. • The security inks and flexible displays of the as-prepared sample were identified.