Terbium and europium co-doped Sr ₈ ZnY(PO ₄ ) ₇ phosphors are successfully prepared through a high temperature solid-state reaction (SSR). The crystal structure of the as-prepared samples was identified to be Sr ₈ ZnY(PO ₄ ) ₇ (SZYP) pure phase by an X-ray powder diffraction technique. Under near-ultraviolet light excitation (378 nm), the SZYP:Tb ³⁺ and SZYP:Eu ³⁺ phosphors show green and red emission peaking at 545 and 618 nm, respectively. Moreover, an effective energy transfer process from Tb ³⁺ to Eu ³⁺ could be verified by the concentration dependence of emission intensity and lifetime. The energy transfer mechanism between Tb ³⁺ and Eu ³⁺ is determined to be governed by dipole-dipole interactions. The internal quantum efficiency (IQE) is evaluated to be as high as about 91%. The temperature-dependent spectra indicate that the SZYP:Tb ³⁺ ,Eu ³⁺ phosphor shows a high thermal stability. Furthermore, the as-fabricated white LED devices exhibit an excellent correlated color temperature (CCT) of 3223 K, a color rendering index (R _a ) of 85.8 and a luminance efficiency of 37.4 lm W ^-1 . All results imply that the SZYP:Tb ³⁺ ,Eu ³⁺ phosphors have a great potential for application in white LEDs.

For plant-growth lighting, novel deep-red emission phosphors with high brightness were obtained by co-doping Ti⁴⁺ and Mn⁴⁺ into a Ca₁₄Al₁₀Zn₆O₃₅ substrate through a conventional solid-state reaction strategy. The nominal Ca_14-(x+y)/2Al_10-x-yZn₆O₃₅:xTi⁴⁺,yMn⁴⁺ (CAZO:Ti⁴⁺,Mn⁴⁺) phosphors could be excited by both near-ultraviolet (NUV) and blue-light-emitting diode (LED) chips efficiently and exhibited a strong deep-red emission band ranging from 650 nm to 750 nm, which should be the result of the ²E → ⁴A₂ transition inside the [MnO₆]^8- octahedral. Multiple energy transfer from Ti⁴⁺ to Mn⁴⁺ was detected in this CAZO; whereby Ti⁴⁺ and Mn⁴⁺ phosphors were verified to be a result of the dipole-dipole interaction under excitation at 270 nm. LED plant-growth lights were fabricated using the as-prepared nominal Ca_13.825Al_9.65Zn₆O₃₅:0.15Mn⁴⁺,0.2Ti⁴⁺,0.005H₃BO₃ (CAZO:Mn⁴⁺,Ti⁴⁺,H₃BO₃) phosphors pumped by a 460 nm blue-chip; this luminaire could be used to greatly promote the cultivation of succulent plants. Combined with the attractive thermal stability as well as high quantum efficiency (QE) of this phosphor, it was demonstrated that these novel phosphors may be candidate deep-red luminescent materials for LED plant lighting.