Ce³⁺-Activated SrLu₂Al₃ScSiO₁₂ Cyan-Green-Emitting Garnet-Structured Inorganic Phosphor Materials toward Application in Blue-Chip-Based Phosphor-Converted Solid-State White Lighting

Abstract

Phosphor-converted white-light-emitting diodes (WLEDs) with superhigh color rendering index (CRI) are the ongoing pursuit of next-generation solid-state lighting. One of the most important challenges is the limited improvement in CRI on account of the absence of a cyan component in the typical commercial combination. Here, a bright broad-band cyan-greene m i t t i n g p h o s p h o r w i t h c u b i c g a r n e t s t r u c t u r e , SrLu 2 Al 3 ScSiO 12 :Ce 3+ (SLASSO:Ce 3+ ), was successfully reported, which can compensate for the absence of cyan cavity in the 480−520 nm blue-green emission region. With 439 nm blue-light irradiation, the as-fabricated SLASSO:Ce 3+ phosphor yields a broad-band cyangreen emission with the maximum emission peak positioned at 525 nm and an appropriate full width at half-maximum (fwhm) of 111 nm, capable of providing more cyan emission component without sacrificing green emission. Meanwhile, the optimal SLASSO:2% Ce 3+ phosphor features CIE color coordinates of (0.3254, 0.5470) with cyan-green hue, along with a high internal quantum efficiency of up to 93%. Additionally, thermal stability measurements at different temperatures reveal that the luminescence emission intensity of the proposed phosphor retains 44% of its original integral emission intensity at 423 K with respect to room temperature, while also demonstrating an excellent color stability (ΔE = 5.4 × 10 −3 ). This work shows that the highly efficient SLASSO:Ce 3+ garnet phosphor can be utilized as a potential cyan-green-emitting phosphor for filling the cyan gap, resulting in the construction of a high-quality warm WLED with high CRI for "human-centric" sunlight-like full-spectrum solid-state illumination.

Sb3+/Sm3+ Codoped Cs2NaScCl6 All-Inorganic Double Perovskite: Blue Emission of Self-Trapped Excitons and Red-Emission via Energy Transfer

“…However, lead-free double perovskites suffer from low luminescence efficiency, posing a challenge in obtaining highly efficient emission. It has been proven that ion doping can effectively regulate the photoluminescence properties of lead-free double perovskites. − There are two mechanisms for enhancing the luminescence efficiency in lead-free halide perovskites by ion doping. First, doping alters the energy band structure and enables electron transitions, resulting in composite luminescence on these bands and emitting characteristic spectra, such as Eu 3+ , Yb 3+ , and Sm 3+ doping into lead-free halide perovskites. − Second, doping can modulate the Jahn–Teller distortion, thus tuning the self-trapped exciton (STE) luminescence.…”