Nowadays, solid-state white light-emitting diodes (wLEDs) have attracted remarkable attention for applications in general lighting, displays and numerous electronical devices due to their eminent efficiency, longer lifetime and higher mechanical durability compared to traditional incandescent and fluorescent lights. In current commercial wLEDs, a combination of Y ₃ Al ₅ O ₁₂ :Ce ³⁺ yellow phosphor with blue LED chip and epoxy resin is generally used to generate white light. However, there are some considerable frailties mostly originated from phosphor and resin such as, degradation upon heat, and moisture, inhomogeneous spectral distribution, and poor color rendering capability. Therefore, phosphor embedded glass-ceramics have been developed as a promising way to obtain durable solid-state lighting devices. However, in these methods, there is a greater risk of reactions between the phosphor material and the glass host. At this point, lanthanide-doped luminescent glasses have drawn great attention as a new generation phosphor and/or epoxy free white-light-emitting source owing to their favorable properties including high thermal and chemical stability, high transparency, and easy manufacturing process. This review article aims to comprehensively summarize the recent progress in singly (i.e., Dy ³⁺ , Eu ²⁺ ), doubly (i.e., Dy ³⁺ /Eu ³⁺ , Dy ³⁺ /Tm ³⁺ , Dy ³⁺ /Ce ³⁺ , Ce ³⁺ /Sm ³⁺ , Ce ³⁺ /Tb ³⁺ ) and triply (i.e., Ce ³⁺ /Tb ³⁺ /Mn ²⁺ , Eu ³⁺ /Tb ³⁺ /Tm ³⁺ , Ce ³⁺ /Tb ³⁺ /Eu ³⁺ , Tm ³⁺ /Tb ³⁺ /Sm ³⁺ , Ce ³⁺ /Dy ³⁺ /Eu ³⁺ , Ho ³⁺ /Tm ³⁺ /Yb ³⁺ , Er ³⁺ /Tm ³⁺ /Yb ³⁺ ) lanthanide-doped glasses for solid-state lighting applications through down-shifting and up-conversion emissions. Theoretical background including energy transfer mechanisms, glass synthesis methods, radiative and colorimetric properties are given in details. Finally, various effective strategies are highlighted that minimize the critical challenges associated with lanthanides—such as providing energy transfer from quantum dots or nanoparticles to lanthanides, and doping lanthanides in low phonon energy glass—to improve the white light emission of luminescent glasses and broaden their application areas.

Three-dimensional (3D) imaging technology holds immense potential across various high-tech applications; however, current display technologies are hindered by limitations such as restricted viewing angles, cumbersome headgear, and limited multi-user accessibility. To address these challenges, researchers are actively exploring new materials and techniques for 3D imaging. Laser-based volumetric displays (VDs) offer a promising solution; nonetheless, existing screen materials fall short in meeting key requirements for long-term durability, full-color operation, and scalability. In this study, we present a comprehensive investigation into easily scalable rare-earth (RE³⁺) doped monolithic glasses (RE = Ho, Tm, Nd, Yb) capable of tunable full-color emission using a novel excitation modulation technique under 808 nm and 980 nm laser excitation and demonstrate their implementation as laser-based VD materials through prototyping. By controlling the movement of lasers’ pulses and galvanometer mirrors with waveform generators, our system generates images in simple and complex shapes with high purity red, green, and blue (RGB) colors. These images can be manipulated, including actions like translation, rotation, expansion, and sequential movement within the monolithic glass screen material. Our findings showcase the potential of glass-based dynamic VDs in revolutionizing display technology, offering superior color purity, vividness, and performance in comparison to conventional display systems.

Emission color tuning of Ho³⁺/Tm³⁺/Yb³⁺ doped glass patterns via focusing and defocusing the laser beam.

Optical thermometry is a non-contact temperature sensing technique with widespread applications. It offers precise measurements without physical contact, making it ideal for situations where contact-based methods are impractical. However, improving the accuracy of optical thermometry remains an ongoing challenge. Herein, enhancing the thermometric properties of luminescent thermometers through novel materials or strategies is crucial for developing more precise sensors. Hence, the present study focuses on the application of four-mode luminescence thermometric techniques in sol–gel synthesized Er³⁺/Yb³⁺ co-doped Ba₂GdV₃O₁₁ phosphors for optical temperature sensing in the temperature range of 298–573 K. The upconversion (UC) luminescence is achieved under excitations of 980 nm or 1550 nm, resulting in bright yellow-green emission in the visible spectral range. Temperature sensing is realized by exploiting the UC emissions of ⁴S_3/2, ²H_11/2 and ⁴F_7/2 bands, which represent intensity ratios of thermally coupled levels (TCELs) and non-thermally coupled levels (NTCELs) of Er³⁺/Yb³⁺, along with the emission lifetimes at ⁴S_3/2. The relative sensitivity (S_r) values for TCELs exhibit a gradual decrease with rising temperature, reaching a maximum of 1.1% K⁻¹ for 980 nm excitation and 0.86% K⁻¹ for 1550 nm excitation at 298 K. Conversely, for NTCELs, the highest S_r value observed is 0.9% K⁻¹ at 298 K for 1550 nm excitation. Moreover, the emission lifetimes at ⁴S_3/2 yield notably high S_r values of up to 5.0% μs K⁻¹ (at 425 K). Furthermore, the studied phosphors have a sub-degree thermal resolution, making them excellent materials for accurate temperature sensing. Overall, this study provides a promising new direction for the development of more precise and reliable optical thermometry techniques, which could have important implications for a range of scientific and industrial optical temperature sensing applications.

Cesium lead bromide (CsPbBr₃) quantum dots (QDs) have shown great potential in the field of luminescent materials owing to their superior optical and electrical properties. However, instability and lack of multicolor emissions resulting from the intrinsic nature of CsPbBr₃ QDs are still the major challenge for their commercialization. Herein, Eu³⁺ and Tm³⁺ co-doped CsPbBr₃ QD glass nanocomposites (GNCs) are successfully synthesized via traditional melt-quenching followed by a heat-treatment route to obtain tunable emission in a durable host material. Tm³⁺ ions are doped to blue-shift the main emission peak of CsPbBr₃ QDs, while Eu³⁺ ions are incorporated to compensate for the red deficiency. Accordingly, a tunable color emission spanning the entire visible spectrum is achieved from GNCs with a fixed composition. The incorporation of Eu³⁺ and Tm³⁺ ions promotes the crystallization of CsPbBr₃ QDs in the glass host resulting in ∼100% photoluminescence quantum yield (PLQY) using a dilution method. The selected glass host has also been proven to effectively protect CsPbBr₃ QDs against chemical, thermal and photo degradation. Interestingly, the selected Eu³⁺/Tm³⁺ co-doped CsPbBr₃ QD GNC shows warm-white light with a low color temperature of 3692 K without utilizing any commercial phosphors. This indicates that the produced GNCs have the potential to be used as light convertor materials in multi-color LED or warm white LED applications due to their robust stability and extremely pure and tunable emission colors.