A novel orange-red-emitting CsSr3Y(PO4)3F:Sm3+ phosphor with high thermal stability for plant growth lighting and WLEDs

Abstract

CsSr₃Y(PO₄)₃F:xSm³⁺ phosphors with fluorapatite structure (x = 1, 2, 5, 10, 15, 20, 25, 30 mol%) were prepared by high-temperature solid-state method. The morphology, optical properties, phase composition, crystal framework, and application scope of the samples were all systematically depicted. The optimal doped concentration of CsSr₃Y(PO₄)₃F:xSm³⁺ is x = 5 mol% and the internal quantum efficiency (IQE) of CsSr₃Y(PO₄)₃F:5 mol%Sm³⁺ is 75.74 %. Under the excitation of 405 nm, the CsSr₃Y(PO₄)₃F:5 mol%Sm³⁺ phosphor shows a main significant emission peak at 601 nm. The emission intensity of CsSr₃Y(PO₄)₃F:5 mol%Sm³⁺ phosphor at 420 K is still 98.33 % of that at 300 K. Furthermore, the prepared phosphor exhibits good thermal stability and remarkable activation energy E_a (0.64 eV). Additionally, the prepared phosphor has a high color purity. The absorption spectra of some common plant pigments (such as chlorophyll b and phycocyanin) are well matched with the spectra of plant supplemental lights. The emission spectra of the orange-red light emitting diode (LED) and their absorption spectra correspond well. The white light emitting diode (WLED) has a total color rendering index (CRI, R_a) of 91 and a relative color temperature (CCT) as low as 4410 K. In conclusion, CsSr₃Y(PO₄)₃F:Sm³⁺ has a wide range of potential applications in plant growth and LEDs lighting due to its exceptional optical and thermal characteristics.