Highly efficient and thermally stable CaMgLaSbO6:Mn4+ red phosphor for indoor plant growth

CaMgLaSbO6 (CMLS): Mn4+ far-red phosphors were successfully synthesized by high temperature solid state reaction. X-ray diffraction (XRD), photoluminescence excitation (PLE) spectra, photoluminescence emission (PL) spectra, ultraviolet-visible spectra, the relationship between emission intensity and temperature and internal quantum efficiency (IQE) were used to analyze the characteristics and optical properties of the samples. It was found that CMLS: Mn4+ phosphor has a strong wide excitation band in the range of 200-550 nm. There is a broad emission band centered at 695 nm between 600 and 760 nm. The optimum doping concentration of Mn4+ is approximately 0.6 mol%. In addition, the chromaticity coordinates of CMLS:Mn4+ appear in the far-red region. The concentration quenching mechanism is attributed to the dipole-quadrupole interaction of Mn4+ ions. Beside, CMLS: 0.006Mn(4+) shows remarkable thermal stability (I-423K/I-298K = 67.1%). Importantly, the IQE of CMLS: 0.006 Mn-4 (+) phosphor was as high as 46.5%. Finally, a 365 nm light emitting diode (LED) chip and CMLS: 0.006Mn(4+) phosphor are used to fabricate the LED device. The above results manifested that CMLS:Mn4+ phosphors are expected to make a contribution to indoor plant cultivation.