A new red phosphor with high thermal stability for plant growth LEDs

The use of artificial light in modern agriculture is essential for increasing crop yields and quality, as well as controlling the growth and development pace of plants. A new series of Mg0.388+xAl2.408-2xMnxO4 (MAO: xMn4+) phosphors was prepared by solid-phase reaction in this study. Under excitation at 339 nm, these phosphors can emit red light peaking 677 nm. By comparing the PL intensity of phosphors MAO: xMn4+ (x = 0.003–0.015), the optimal concentration of Mn4+ is x = 0.009. The concentration quenching effect was found to occur at concentrations above this level. Moreover, it has good thermal stability, and when compared to 300 K, its overall intensity is 51.7% at 450 K. Finally, a prototype LED device is successfully fabricated by coating a 420 nm blue LED chip and MAO:0.009Mn4+ red phosphor, with the electroluminescent significantly overlap with the Chlorophyll a. This leads to the implication that the phosphor MAO:0.009Mn4+ can be used to produce LED lamp for plant growth.