Novel narrow-band blue-emitting Cs3Zn6B9O21:Bi3+ phosphor with superior thermal stability

Abstract

Exploring novel narrow-band luminescent materials is of great significance for light-emitting-diode and display applications. In this study, we successfully designed a blue emitting narrow-band Cs₃Zn₆B₉O₂₁:Bi³⁺ phosphor based on the doping of Bi³⁺ ions into a three-dimensional (3D) layer network. The as-prepared Cs_2.98Zn₆B₉O₂₁:0.02Bi³⁺ phosphor shows an extraordinary narrow-band blue emission from 390 to 500 nm centered at 436 nm with a full width at half maximum (FWHM) of 50 nm. The corresponding color purity of blue light could reach 95.1%. Surprisingly, the Cs_2.98Zn₆B₉O₂₁:Bi³⁺ phosphor could maintain 100% photoluminescence integrated intensity at 150 °C, and showed only a 23% drop of the initial intensity at 250 °C, implying low thermal quenching. The superior thermal stability is ascribed to the compensation of emission loss via energy transfer from charge traps to the luminescent center. The establishment of the relationships between the narrow-band emission and crystal structure can also be applied to design other novel narrow-band phosphors for optical applications.