CaAlSiN3:Eu2+/Lu3Al5O12:Ce3+ phosphor-in-glass film with high luminous efficiency and CRI for laser diode lighting

Abstract

Laser diode (LD) driven lighting is expected to be the next-generation lighting, and red CaAlSiN₃:Eu²⁺ (CASN) phosphor is still required for high-quality LD white lighting. Utilizing glass with a suitable thermal expansion coefficient and low softening temperature as the inorganic binder, CASN phosphor-in-glass-films (PiFs) are fabricated in this work. High efficiency and thermal stability are achieved by optimizing the reaction of CASN and glass. Introducing Lu₃Al₅O₁₂:Ce (LuAG) to offset the luminous spectra of CASN PiFs, broad emission spectra and high efficiency are recorded. High color rendering index (CRI, 88.6), luminous efficiency (LE, 153 lm W⁻¹), and luminous flux (LF, 1162 lm) are achieved simultaneously when the PiFs are excited by a 455 nm blue LD. At last, the high color quality LD white lighting produced by PiFs is displayed for the first time. We believe that the results provided by this work are an enormous progress for PiFs and encourage more researchers to provide new strategies to acquire high performance of PiFs in white LD lighting.