A novel reddish‐orange emitting NaSrBiTeO₆:Sm³⁺ phosphor with high moisture resistance and thermostability for horticultural light emitting diode applications

Abstract

A sequence of reddish‐orange emitting NaSrBi(1−x)TeO6:xSm3+ phosphors were successfully composited by a favorable solid‐phase chemical process. The sintering temperature is optimized as 850°C. NaSrBiTeO6 (NSBTO):Sm3+ samples were assigned to the cubic double‐perovskite structure, exhibiting the space group of Fmm (225). Photoluminescence emission spectra display the main peaks at 562, 598, 645, and 705 nm at 404 nm excitation. Among them, the most intense emission peak is at 645 nm. The concentration‐quenching mechanism of Sm3+ follows the interaction between electric dipoles and quadrupoles. The asymmetric ratio (I(4G5/2‐6H9/2)/I(4G5/2‐6H5/2) of NSBTO:2 mol%Sm3+ phosphor is extracted as 4.96. The optimum NSBTO:2 mol%Sm3+ phosphor has excellent thermal stability with a remained emission intensity riches 93.61% (420 K). After testing with high‐pressure water steam at various periods, the phosphor remains chemically stable for moisture resistance. For the NSBTO:2 mol%Sm3+ phosphor, the satisfactory color purity and low correlated color temperature (CCT) are obtained with 99.9% and 1494 K, respectively. The electroluminescence spectra of the prepared red light emitting diode (LED) are in conformity with the phytochrome absorption spectra of chlorophyll a, chlorophyll b, PFR, and PR. The white light‐emitting diode (w‐LED) is also perfectly packaged, obtaining an efficient color rendering index (Ra) of 92.12 and CCT of 5553 K. These exceeding optical properties certified that NaSrBi(1−x)TeO6:xSm3+ demonstrates promising prospects and can be efficiently applied in horticultural LED applications.

Temperature-dependent self-trapped models regulating energy transfer in rare earth double perovskites via 5s2 electron doping

“…The excitation peak at 410 nm originates from the 6 H 5/2 → 4 F 7/2 transition of the Sm 3+ ion. 31 The profiles of the PLE in NIR emission in Fig. 2c is similar to that in Fig.…”

Effect of Pyrrolidinedithiocarbamate Ligand on the Luminescence Properties of Heteroligand Samarium and Europium Complexes: Experimental and Theoretical Study

“…The luminescence spectrum of powder Sm­(pdtc) 3 (phen) at λ ex = 340 nm (Figure ) consists of four distinct peaks, corresponding to Sm 3+ f–f transitions. They are assigned to 4 G 5/2 → 6 H 5/2 (564 nm, Δ J = 0, where J represents total angular momentum), 4 G 5/2 → 6 H 7/2 (598 nm, Δ J = 1), 4 G 5/2 → 6 H 9/2 (645 nm, Δ J = 2), and 4 G 5/2 → 6 H 11/2 (706 nm, Δ J = 3). − The luminescence of the Sm-complex was quite visible to the naked eye. The hypersensitive electric dipole transition 4 G 5/2 → 6 H 9/2 (645 nm) was the most intense one, followed by 4 G 5/2 → 6 H 7/2 (598 nm).…”