A novel single-phase trivalent europium activated red-emitting SrLaNaTeO 6 phosphor was first synthesized in a process of traditional high-temperature solid-state. The phase purity, morphology, and spectroscopy of the prepared phosphor were analyzed. Under 395 nm excitation, the photoluminescence (PL) spectra of the SrLaNaTeO 6 :Eu 3+ products mainly contained five dominant sharp peaks. The intense red emission peak at 615 nm was the typical 5 D 0 → 7 F 2 electric dipole transition of Eu 3+ . The optimum product of high quenching concentration was the SrLaNaTeO 6 :0.90Eu 3+ , which reached a high internal quantum efficiency (IQE) of 90.6%. The SrLaNaTeO 6 :0.90Eu 3+ was estimated to have R c of 6.57 Å and possessed high color purity of 100.0%. The phosphors exhibited excellent thermal stability and high activation energy ( E a = 0.29 eV). The prepared white light-emitting diode (WLED) had a high color rendering index (CRI) R a of 92 and a low correlated color temperature (CCT) of 5008 K. In conclusion, the phosphors have potential as red components for WLEDs.
A novel deep-red phosphor with Mn 4+ -doped double perovskites SrLaNaTeO 6 (SLNTO) was synthesized by the conventional high-temperature solid-state method. SLNTO contains both [NaO 6 ] and [TeO 6 ] octahedra. The octahedral structure of double perovskites facilitates the doping of Mn 4+ . The band gap ( E g ) of the direct semiconductor SLNTO is 2.88 eV. With an excitation wavelength of 322 nm, SLNTO:Mn 4+ has a 700 nm deep-red wavelength emission assigned to the energy level transition from 2 E 1g to 4 A 2g of Mn 4+ ions. Photoluminescence (PL) of the sample and phytochrome far-red light (P FR ) absorption are satisfactory matches. According to the Tanabe-Sugano diagram, Mn 4+ is located in the strong crystalline field for 2 E 1g . A 2.0 mol% concentration of Mn 4+ is optimal; further high doping results in concentration quenching, ascribed to the neighbour ion interaction and dipole‒dipole ( d-d ) interactions. The internal quantum efficiency (IQE) is 87.84 %. Additionally, the electroluminescent (EL) spectrum of the encapsulated plant growth lamp overlaps with the chlorophyll a and b absorption spectra . Its Commission Internationale de l'Eclairage (CIE) coordinates of SLNTO:2.0 mol%Mn 4+ phosphor with a near-ultraviolet (n-UV) chip are located in (0.720, 0.280). The phosphor-converted white light-emitting diode (pc-WLED) has a high colour rendering index ( R a = 96) with a suitable correlated colour temperature (CCT = 6240 K). The results are satisfactory for white light-emitting diodes (w-LEDs) and plant growth lamps.
危险品化学品经营许可证（带存储）