Red emitting Eu3+ doped Sr3La2(BO3)4 phosphors for LED and anti-counterfeiting applications

Abstract

A series of Eu 3 + -activated Sr 3 La 2 (BO 3 ) 4 (SLB) orange-red phosphors were synthesized via a high-temperature solid-state method. Under 394 nm excitation, the optimal phosphor exhibits orange-red emission with a dominant peak at 612 nm ( 5 D 0 → 7 F 2 ) and a color purity of 92.5%. The optimal doping concentration is 0.09 mol, and concentration quenching is governed by electric quadrupole–quadrupole ( q - q ) interactions. The phosphor shows good thermal stability, retaining 71% at 150 °C. A red LED device fabricated with the optimal phosphor exhibits a low correlated color temperature (2259 K) with high color stability. Furthermore, the phosphor demonstrates potential in anti-counterfeiting applications, showing bright orange-red patterns under UV excitation. These results highlight the promise of this phosphor for near-UV-excited red LEDs and anti-counterfeiting.