Cationic substitution induces multicolor emission in YBaZn3-yMgyGaO7: Bi3+ phosphors for WLEDs and information encryption

Currently, the development of innovative, efficient phosphors featuring near-ultraviolet excitation and broadband emission, notably Bi 3+ -activated phosphor, is pivotal for realizing high-performance white light-emitting diodes (WLEDs). In this work, we report a series of broadband orange-green emitting YBaZn 3- y Mg y GaO 7 : Bi 3+ phosphors with strong n-UV excitation. By employing cationic substitution, we successfully tuned the emission wavelength from 605 to 550 nm, thereby unlocking potential for multifunctional applications in solid state lighting and information encryption. YBaZn 3 GaO 7 : 0.015Bi 3+ phosphor generates 605 nm orange emission with a full width at half-maximum (FWHM) of 220 nm under 330 nm n-UV excitation, with high luminescence intensity and excellent thermal stability. In addition, the luminescence mechanism of Bi 3+ ions in YBaZn 3- y Mg y GaO 7 : Bi 3+ was investigated thoroughly. A high-performance W-LED device has been fabricated, utilizing a unique YBaZn 3 GaO 7 : 0.015Bi 3+ phosphor and commercial blue and green phosphors, pumped by a 365 nm chip. This phosphor-converted (pc) WLED has an excellent color-rendering index (R a ) of 95.6 and a comfortable correlated color temperature (CCT) of 5193 K. This result indicates its potential applications in the field of health lighting. Furthermore, the orange-green YBaZn 3- y Mg y GaO 7 : Bi 3+ phosphor demonstrates precise information identification in information encryption, confirming its potential in this field.