Sm³⁺ luminescence has pivotal significance in the field of optoelectronics. However, their poor luminescence efficiency severely hinders their practical application as Sm³⁺-activated optical materials. Herein, two whitlockite-type phosphors, Sr₉Ln(PO₄)₇:Sm³⁺ (Ln = La and Y, marked as SLPO and SYPO), with anti-thermal quenching (ATQ) were reported. The substitution of La³⁺ with Y³⁺ results in structural evolution from the space group R $\overline{\mathbf{3}}$m of SLPO:Sm³⁺ to I2/a of SYPO:Sm³⁺, increasing the distance between Sm³⁺ dopants and suppressing nonradiative (NR) relaxation. The luminescence efficiency is significantly enhanced by 2.3 times. The representative SYPO:0.05Sm³⁺ phosphor demonstrates superior temperature sensing performance, achieving a relative sensitivity of 1.78%·K⁻¹, which exceeds the values reported for recently investigated Sm³⁺-activated phosphors. Moreover, the material is packaged in a 395 nm chip-excited white lighting source, resulting in a low correlated color temperature (CCT = 3394 K) with a high color rendering index (R_a = 97). This study provides a facile structural evolution strategy for designing highly efficient Sm³⁺-activated optical materials that facilitate wider applications.

Despite advances in the multicolor luminescence of Ce-activated materials, achieving efficient and stable near-ultraviolet (n-UV) emission remains a critical challenge. On the basis of structural rigidity engineering, a small Stokes shift (ΔS = 0.53 eV) of Ce in microwave-hydrothermally synthesized NaSrY(PO₄)₂ (NSYP) nanophosphors is achieved, addressing this shortage. The internal quantum efficiency reaches as high as 98.5% (λ_ex = 325 nm) along with superior thermostability (78% intensity retention at 423 K) and exceptional solvent resistance (82% after 10 days of immersion). The optimal nanomaterial is used as a scintillation screen for X-ray imaging, achieving a high spatial resolution of 11.0 lp/mm and clear imaging of measured objects, rivaling a commercial scintillator (CsI:Tl). A high relative sensitivity (S_R-max = 0.94 (%)·K⁻¹) is achieved for excitation intensity ratio (EIR) technology-based optical thermometry. This work presents fascinating applications in X-ray imaging and optical thermometry for n-UV-emitting nanophosphors. These findings also highlight the critical role of host structure in designing high-quality Ce-activated optical materials.

For noncontact optical thermometry, in contrast with fluorescence intensity ratio (FIR) technology, excitation intensity ratio (EIR) technology has been seriously limited due to low sensitivity. Moreover, by exploring all possible temperature-dependent response, developing multimode optical thermometry is of great importance. In this work, a new Na₂Y₂TeB₂O₁₀ (NYTB):Tb³⁺ phosphor is obtained by a solid-state reaction. Based on FIR and EIR models of Tb³⁺, thermometric properties are studied thoroughly. Excellent relative and absolute sensitivity (S_R and S_A) are acquired due to the significant difference in emission/excitation lines in response to temperature. Meanwhile, Tb³⁺ content-dependent luminescence quenching mechanism is discussed. This study shows a feasible route for exploiting well-performing FIR-/EIR-based thermometric materials.

Exploring outstanding rare-earth activated inorganic phosphors with good thermostability has always been a research focus for high-power white light-emitting diodes (LEDs). In this study, we report a Sm³⁺-activated KNa₄B₂P₃O₁₃ (KNBP) powder phase. Its particle morphology, photoluminescence properties, concentration quenching mechanism, thermal quenching mechanism, and chromatic properties are demonstrated. Upon the near-ultraviolet (NUV) irradiation of 402 nm, the powder phase exhibits orange-red visible luminescence performance, originating from typical ⁴G_5/2→⁶H_J/2 (J = 5, 7, 9) transitions of Sm³⁺. Importantly, the photoluminescence performance has good thermostability, low correlated color temperature (CCT), and high color purity (CP), indicating its promising application in the NUV-pumped warm white LEDs.