No abstract

Recently, trivalent chromium ion doped phosphors have exhibited significant application potential in broadband near-infrared (NIR) phosphor-converted light-emitting diodes (pc-LEDs). However, developing an NIR phosphor with both broad emission bandwidth and excellent luminescence thermal stability is still a great challenge. Here, we demonstrate an NIR phosphor, ScF3:Cr3+, which can fulfill both conditions simultaneously. The prepared phosphors show broadband emission in the range of 700 to 1100 nm, with a full width at half-maximum (FWHM) of 140 nm peaking at 853 nm. These phosphors also demonstrate an excellent luminescence thermal stability (the emission intensity of ScF3:Cr3+ keeps 85.5% at 150 °C compared with the value at room temperature). An NIR pc-LED based on blue LED chips was fabricated and tested. The results show that the NIR pc-LED can yield strong broadband NIR emission. This work not only provides a promising phosphor for the application of NIR pc-LEDs but also has important guiding significance for effect of synthesis conditions on the luminescence properties of Cr3+-doped fluorides.

The improvement of high‐performance narrow‐band green phosphors in backlight display applications is still a major challenge. Based on the UCr4C4 type of oxide phosphor, the high‐performance narrow‐band green phosphors Rb3M(Li3SiO4)4:Eu2+ (M = Rb or Na) are studied in different luminous positions. Benefiting from the replacement of Rb by Na, the change of the local environment in the crystal structure of Rb3Na(Li3SiO4)4:Eu2+ (R3NLSO:Eu2+) leads to the decrease of Stokes shift, which improves the quantum efficiency. Moreover, change in the local environment enhances the structural rigidity, which makes the thermal and chemical stability better. The R3NLSO:8%Eu2+ phosphor presents a narrow‐band green emission centered at 527 nm, excellent thermal stability (102% @150 °C of the integrated emission intensity at room temperature), and high internal/external quantum efficiency (85.3%/40.4%). The white light‐emitting diode (wLED) using R3NLSO:8%Eu2+ phosphor presents a superior luminous efficiency of 128.3 lm W‐1 and a wide color gamut. All the results indicate that R3NLSO:8%Eu2+ green phosphor has great application prospects in the field of liquid crystal display. This work also provides important guiding significance for the optimization of alkali metal element type of phosphors.

Currently, the temperature sensing performances of inorganic photoluminescence materials based on fluorescence intensity ratio technology have become research hotspot in the optical thermometry field due to its non-contact, fast response...

No abstract