Li₂SrSiO₄:Ce³⁺, Pr³⁺ Phosphor with Blue, Red, and Near‐Infrared Emissions Used for Plant Growth LED

Abstract

Ce3+/Pr3+ codoped Li2SrSiO4 (LSS) phosphors with blue, red, and near‐infrared (NIR) tri‐emission have been prepared via a high‐temperature solid‐state reaction method. Under the excitation of 200 to 400 nm near‐ultraviolet (n‐UV), the photoluminescence (PL) spectra of phosphors are composed of visible and NIR two parts. The former exhibits blue and red emission bands centered at around 428 nm from 5d–4f transition of Ce3+ and 611 nm from 1D2 → 3H4 transition of Pr3+, those overlap with photosynthesis action spectra of plants and absorption spectra of chlorophylls and carotenoids. While the later presents a broad NIR emission band peaking near 1039 nm caused by the 1G4 → 3H4 of Pr3+, matching with the absorption of bacteriochlorophyll. Their emission intensity ratios (B: R: NIR) could be tuned by altering the relative ratios of Ce3+ and Pr3+ concentration in the phosphors to meet the requirements of multifarious plants and bacteria. The efficient energy transfer from Ce3+ to Pr3+ takes place in the LSS host, which ascribed to an exchange interaction according to PL spectra and decay curves of phosphors. Results suggest that the present LSS: Ce3+, Pr3+ phosphors have great potential applications in plant growth n‐UV LED.

Photoluminescence and afterglow behavior of Ce3+ activated Li2Sr0.9Mg0.1SiO4 phosphor

“…This phenomenon results from the concentration quenching, which was studied by Chen. 27 These results demonstrate that the optimal doping concentration of Ce 3+ in Li 2 Sr 0.9 Mg 0.1 SiO 4 experimentally determined to be 0.4 at%.…”

Novel Mn4+-activated LiLaMgWO6far-red emitting phosphors: high photoluminescence efficiency, good thermal stability, and potential applications in plant cultivation LEDs

“…It is known that light is essential for plant growth, especially blue light (440 nm) and red light (660 nm), which can promote the synthesis of carbohydrates; in other words, both lights can act as the energy source to accelerate photosynthesis. [16][17][18] However, only these two lights are not sufficient. Researchers have shown that two types of phytochromes in plants have signicant effects on the growth of plants; one is P FR , which can switch to another type, P R , by absorbing a certain amount of far-red light (730 nm), and P R can also transform back to P FR aer exposure to red light (660 nm).…”

Tunable emission color of Li2SrSiO4:Tb3+ due to cross‐relaxation process and optical thermometry investigation

“…Eu 2+ ‐doped Li 2 SrSiO 4 shows strong and broad orange‐yellow emission centered at about 562 nm . Ce 3+ /Pr 3+ codoped Li 2 SrSiO 4 phosphors with blue, red and near‐infrared triemission could be potentially used for plant growth LEDs . Recently, long afterglow behavior is observed in a novel green‐emitting phosphor Li 2 Ca 0.4 Sr 0.6 SiO 4 :Tb 3+ .…”

“…22 Ce 3+ /Pr 3+ codoped Li 2 SrSiO 4 phosphors with blue, red and near-infrared triemission could be potentially used for plant growth LEDs. 23 Recently, long afterglow behavior is observed in a novel green-emitting phosphor Li 2 Ca 0.4 Sr 0.6 SiO 4 :Tb 3+ . 24 However, the work related to specific characteristics of Tb 3+ , for instance, cross relaxation, tunable emission, and optical thermometry in Li 2 SrSiO 4 is rare.…”