Dy3+@Mn4+ co-doped Ca14Ga10-mAlmZn6O35 far-red emitting phosphors with high brightness and improved luminescence and energy transfer properties for plant growth LED lights

A novel substrate of Ca14Ga10 mAlmZn6O35 (CGAZO) was successfully synthesized via a high-temperature solid-state reaction method and co-doped with Dy3+ and Mn4+ to form a new deep red phosphor (CGAZO: Dy3+, Mn4+) for plant growth LED lighting. This extraordinary phosphor can exhibit strong far-red emission with a maximum peak at 715 nm between 650 and 750 nm, and other four shoulder peaks at 680, 689, 698 and 706 nm, which can be ascribed to 2E(g) `-> 2A(g) spin-forbidden transition of Mn4+. X-ray diffraction (XRD) patterns clarified that Ga3+ sites in the host were partly replaced by Al3+ ions. Moreover, an effective energy transfer from Dy3+ to Mn4+ in the CGAZO host had been verified since linear reduction of emission intensities and decay times of the Dy3+ emission of the phosphors CGAZO: Dy3+, Mn4+ with increasing concentration of Mn4+ was observed. Finally, a LED device was fabricated using a 460 nm blue-chip, silicon gel, and the as-obtained far-red emitting CGAZO: Dy3+, Mn4+ phosphors. The results of the tobacco plant cultivation lighting by this LED device indicate that the as-prepared phosphor has a potential application in the agricultural industry.