The semiconductor oxide BiVO₄ was adopted as a novel host for highly efficient upconversion luminescence and non-contact temperature sensing.

A novel Er³⁺-sensitized spatially confined multilayered nanostructure was constructed resulting in a remarkable enhancement of the NIR II-responsive photon upconversion.

Although much effort has been focused on thermally enhanced upconversion (UC) luminescence, it remains a challenge to maintain or even enhance the UC luminescence of NaLnF₄-based phosphors (Ln = Y, Gd, Lu) using a surface-independent strategy. In this work, we demonstrate that the effect of temperature on UC luminescence in NaGdF₄:Nd³⁺/Yb³⁺/Er³⁺ nanocrystals is strongly dependent on the exciting wavelength. When excited using 808 nm radiation, the UC luminescence exhibits good resistance to thermal quenching. The reason is that, in this situation, the negative effect of multi-phonon decay can be fully compensated by the thermal enhancement in the transition cross-section and in energy-transfer rate. Our research reports a novel strategy for the anti-thermal quenching of upconversion luminescence, which is potentially applicable in the design of dynamic UC anti-counterfeiting as well as in NIR-I-responsive thermometers and nanoheating.

A novel green up-conversion luminescence material, K ₃ LaTe ₂ O ₉ :Er, was synthesised via a solid-state reaction method.

Persistent luminescence (PerL) phosphors have been widely applied in many advanced applications in the field of emergency lighting, safety signage, and ornaments. Recently, the PerL phosphors based on germanates have attracted great attention owing to their excellent PerL performance. However, the design and development of excellent germanates-based PerL materials with full spectral emissions remain challenging due to the lack of color-tunable PerL, especially in the blue and green regions (400–600 nm). Herein, we develop a new type of Tb³⁺-activated LiYGeO₄ PerL phosphor with real-time adjusting the photoluminescence (PL) and PerL color, which can be effectively excited by a 254 UV light. Both blue and green PerL are realized simultaneously in a single phosphor. When LiYGeO₄:Tb³⁺ doped with lower concentrations of Tb³⁺ ions, phosphors emit blue PL and PerL. With increasing Tb³⁺ concentration, the PL and PerL colors of LiYGeO₄:Tb³⁺ PerL phosphor are gradually regulated from blue to green. Besides, LiYGeO₄:Tb³⁺ exhibits temperature-dependent luminescence property, whose PL and PerL colors can also be successively widely tuned by various temperature. This stable and tunable color in real-time PL and PerL property promote the as-designed LiYGeO₄:Tb³⁺ phosphor to have potential applications in advanced anti-counterfeiting and display devices.