Continuously tunable broadband emission of Mn²⁺‐doped low‐melting point Sn–F–P–O glasses for warm white light‐emitting diodes

Abstract

Tin fluorophosphate (TFP) glass, which can be used to manufacture a phosphor‐in‐glass (PiG) for achieving high‐power white light‐emitting diodes (w‐LEDs), has attracted a great deal of attention because of its low‐melting point. Mn2+‐doped ultralow glass transition temperature (~122°C) Sn–F–P–O glasses were prepared to achieve broadband visible light emission from 390 to 720 nm. By controlling the concentration of MnO, the emission color of the TFP glass can be adjusted from blue/cool white to warm white/red. In particular, 0.2 mol% MnO‐doped TFP glass, which yields bright and warm white light and has ultralow glass transition temperature and thermal stability, has a promising application prospect in the field of high‐power w‐LEDs.

Tunable white light in trivalent europium single doped tin fluorophosphates ultra-low melting glass

“…Hirokazu Masai et al firstly reported that SnO-ZnO-P 2 O 5 low-melting glasses showed a broadband blue luminescence with high efficiency, which was described as the emission of Sn 2+ defects as an activation center in the subsequent research [12][13]. Simultaneously, an adjustable white light emission with a high value of quantum efficiency (QE) was obtained by doping Mn 2+ ions into the SnO-ZnO-P 2 O 5 glass matrix [14]. In the tin fluorophosphates glass matrix (SnF 2 -P 2 O 5 -SnO), Wang et al reported a similar broadband visible luminescence, which was also recognized as the contribution of the Sn 2+ centers.…”

Color‐tunable and white emission of Tm3+ doped transparent zinc silicate glass‐ceramics embedding ZnO nanocrystals

“…These systems possess high light efficiency. Nevertheless, they also suffer from some drawbacks, such as light scattering as a result of the refractive index mismatch between phosphors and the encapsulant epoxy resins, complicated manufacturing process and reduced lifetime caused by the low heat resistance of epoxy resins, and possible color change owing to the different degradation rates of the individual components …”

“…It possesses not only advantages of glass matrix but also unique optical properties of the precipitated nanocrystals. Therefore, single‐host luminescent glass‐ceramic is considered as a suitable alternative for W‐LEDs due to its efficient luminescence, higher thermal and chemical stabilities, epoxy resin‐free assembly process and easy formability . In a recent study, we reported that ZnO nanocrystal‐doped transparent glass‐ceramics exhibited intensive yellow emission with short‐time heat treatment when excited by NUV light .…”

“…Nevertheless, they also suffer from some drawbacks, such as light scattering as a result of the refractive index mismatch between phosphors and the encapsulant epoxy resins, complicated manufacturing process and reduced lifetime caused by the low heat resistance of epoxy resins, and possible color change owing to the different degradation rates of the individual components. 5,6 Alternatively, glass-ceramic is a hybrid material that consist of disordered glassy matrix and ordered crystalline phase, usually prepared by controlled crystallization of the precursor glass with appropriate chemical compositions via meltquenching method followed by heat treatment. It possesses not only advantages of glass matrix but also unique optical properties of the precipitated nanocrystals.…”

“…Therefore, singlehost luminescent glass-ceramic is considered as a suitable alternative for W-LEDs due to its efficient luminescence, higher thermal and chemical stabilities, epoxy resin-free assembly process and easy formability. 1,[6][7][8] In a recent study, we reported that ZnO nanocrystal-doped transparent glassceramics exhibited intensive yellow emission with short-time heat treatment when excited by NUV light. 9 On the other hand, rare earth (RE) ions, which possess 4f → 4f transition with narrow and strong band emission, have been widely used to gain abundant emission colors.…”