NUV-pumped luminescence of thermally stable samarium-activated alkali metal borophosphate phosphor

Abstract

Exploring outstanding rare-earth activated inorganic phosphors with good thermostability has always been a research focus for high-power white light-emitting diodes (LEDs). In this study, we report a Sm3+-activated KNa4B2P3O13 (KNBP) powder phase. Its particle morphology, photoluminescence properties, concentration quenching mechanism, thermal quenching mechanism, and chromatic properties are demonstrated. Upon the near-ultraviolet (NUV) irradiation of 402 nm, the powder phase exhibits orange-red visible luminescence performance, originating from typical 4G5/2→6HJ/2 (J = 5, 7, 9) transitions of Sm3+. Importantly, the photoluminescence performance has good thermostability, low correlated color temperature (CCT), and high color purity (CP), indicating its promising application in the NUV-pumped warm white LEDs.

Characterization of Sm3+-activated carbonated calcium chlorapatite phosphors for theranostic applications: a comparative study of co-precipitation and hydrothermal methods

“…The excitation spectra consist of multiple peaks from the 6 H 5/2 ground level to other multiple characteristic levels of Sm 3+ ions present at 318.5, 332.7, 345.7, 362.8, 376.6, 403.6, 417.5, 441.0, 465.2, and 478.0 nm corresponding to the 6 H 5/2 → 2 L 15/2 , the 6 H 5/2 → 4 G 9/2 , the 6 H 5/2 → 4 H 9/2 , the 6 H 5/2 → 4 D 3/2 , the 6 H 5/2 → 6 P 7/2 , 4 D 1/2 , the 6 H 5/2 → 4 F 7/2 , the 6 H 5/2 → 4 P 5/2 , the 6 H 5/2 → 4 G 5/2 , 4 G 9/2 , the 6 H 5/2 → 4 I 13/2 , and the 6 H 5/2 → 4 I 11/2 transitions, respectively. 31–33 The intensity of all the peaks decreases with the increasing concentration of Sm 3+ ions in both preparation techniques. The excitation spectra are the most intense in the case of 0.5 mol% Sm 3+ dopants and less intense in the case of 5 mol% Sm 3+ dopants.…”

“…The colour purity was also assessed for further understanding the colour properties of the obtained red-emitting phosphors, defined as follows: 6 where ( x , y ) is the CIE coordinate of the studied material, ( x i , y i ) is the CIE coordinate of the white-light illumination with a standard value of (0.310, 0.316) and ( x d , y d ) is the colour coordinate of the dominated wavelength with a value of (0.624, 0.376). 6,32,35 The calculated values of colour purity for materials are gathered in Table 2. The colour purity of the emission was calculated to be in the range of 90–96%.…”

“…H 5/2 ground level to other multiple characteristic levels of Sm 3+ ions present at 318.5, 332.7, 345.7, 362.8, 376.6, 403.6, 417.5, 441.0, 465.2, and 478.0 nm corresponding to the 6 H 5/2 -2 L 15/2 , the 6 H 5/2 -4 G 9/2 , the 6 H 5/2 -4 H 9/2 , the 6 H 5/2 -4 D 3/2 , the 6 H 5/2 -6 P 7/2 , 4 D 1/2 , the 6 H 5/2 -4 F 7/2 , the 6 H 5/2 -4 P 5/2 , the 6 H 5/2 -4 G 5/2 , 4 G 9/2 , the 6 H 5/2 -4 I 13/2 , and the 6 H 5/2 -4 I 11/2 transitions, respectively [31][32][33]. …”

Thermometric properties of Na 2Y 2TeB 2O 10:Tb 3+ green phosphor based on fluorescence/excitation intensity ratio

“…For optical temperature measurements, diverse strategies have been developed such as fluorescence intensity ratio (FIR), excitation intensity ratio (EIR), fluorescence lifetime, and emission intensity/position/ bandwidth [10][11][12][13][14]. The mechanism of the FIR/EIR for optical thermometry focuses on studying the relationship between the FIR/EIR and the temperature [15].…”

Superlattice-stabilized structure and charge transfer assisted photoluminescence enhancement in a samarium-doped high entropy perovskite oxide

“…[1][2][3][4] As the core of pc-LEDs, phosphor materials have been extensively explored for achieving desirable PL performance. 5,6 Generally, an LED phosphor material is composed of an activator and a host material. The activators are doped into a host material to produce luminescence properties.…”