Sr4Al14O25:Li+,Mn4+ phosphor-in-glass film: erosion behavior and luminescence property

Abstract

At present, phosphor-in-glass is regarded as a superior encapsulation material substituting for organic materials to resolve the poor thermal stability of WLEDs. However, the serious erosion reaction between commercial red phosphor and the glass matrix restricts the development and application of red phosphor-in-glass. In this work, a novel Sr₄Al₁₄O₂₅:Li⁺,Mn⁴⁺ (SAO) red phosphor-in-glass film (PiGF) with precursor glass xB₂O₃–(85 − x)Bi₂O₃–5Al₂O₃–10CaO was prepared using a low-temperature sintering technique. Crystallization was observed in the precursor glass with 40% and 45% B₂O₃ content at 570 °C for 30 min, with the crystalline phase mainly being Bi₄B₂O₉. The glass transition temperature gradually increases from 420 to 496 °C with an increase in B₂O₃ content from 40 to 60%. The DSC simulation and experimental results show that the degree of erosion of SAO phosphors decreases with an increase in B₂O₃ content from 50 to 60% and with an increase in the co-sintering temperature from 570 to 590 °C, while the glass surface smoothness of the PiGFs decreases with increasing B₂O₃ content. 55% B₂O₃ and 570 °C are the optimal parameters. The PL and PLE of the PiGFs show that the luminous intensity increases and then decreases with increasing B₂O₃ content, with 55% B₂O₃ also being the optimal value. The PiGF shows a quantum efficiency of 46.62%, and the luminous intensity maintains 85.1% of its initial intensity at 348 K.