Orange-Red Emitting Pr~(3+) Doped NaSrBO_3 Nanophosphors: Luminescence and Optical Studies

摘要

Orange-red emitting Pr~(3+) doped NaSrBO_3 nanophosphors were synthesized through a combustion process using metal nitrates as precursors and urea as fuel. Structural, optical and luminescence properties of the phosphors were investigated by using powder X-ray diffraction, diffuse reflectance (DR) spectroscopy and pho-toluminescence (PL) spectroscopy, respectively. The diffraction peaks of the phosphors confirmed the formation of the monoclinic phase of NaSrBO_3 with space group P2_1/c. The nanophosphors have crystallite sizes ranging from 22 to 35 nm. Under 444 nm excitation, the NaSrBO_3:Pr~(3+) nanophosphor showed orange-red emission due to the main emission peak at 607 nm which corresponded to the 4f-4f characteristic transition of the Pr~(3+)(~1D_2 → ~3H_4). The PL intensity of the nanophosphors was improved due to better crystallinity after post-combustion annealing at 800 °C. The DR spectrum of the phosphor was consistent with the excitation spectrum. The calculated CIE coordinates (x = 0.59, y = 0.36), corresponded to the reddish-orange shade of the color gamut.