NUV light induced visible emission in Er³⁺‐activated NaSrLa(MoO₄)O₃ phosphors for green LEDs and thermometer

Abstract

Er3+‐activated NaSrLa(MoO4)O3 phosphors were synthesized by a traditional solid‐state reaction technique, which exhibited bright green emissions ascribing to the (2H11/2, 4S3/2) → 4I15/2 transitions of Er3+ ions under 377 nm excitation. The luminescence intensity increased with increasing the Er3+ ion concentration and achieved its maximum value when the doping concentration was 4 mol%. Moreover, the critical distance was estimated to be 25.32 Å, and the dipole‐dipole interaction played a significant role in NR energy transfer between Er3+ ions in NaSrLa(MoO4)O3 host lattices. At a forward bias current of 100 mA, the Light Emitting Diode (LED) device emitted a bright green emission with the color coordinate of (0.2547, 0.5996) that can be observed by the naked eye. Besides, based on the thermally coupled levels of 2H11/2 and 4S3/2, the temperature sensing performances of the prepared phosphors in the temperature range of 303‐483 K were studied using the fluorescence intensity ratio technique. The maximum sensor sensitivity was about 0.0150 K−1 when the temperature was 483 K, and the Er3+ ion concentration largely influenced the sensor sensitivity of studied samples. Furthermore, the prepared phosphors exhibited excellent water resistance and thermal stability behavior. These characteristics demonstrated that the Er3+ activated NaSrLa(MoO4)O3 phosphors were dual‐functional materials for solid‐state illumination and non‐contact temperature measurement.

Rational Design of Ratiometric Luminescence Thermometry Based on Thermally Coupled Levels for Bioapplications

“…Therefore, different relations between dopant concentration and thermal sensitivity were reported in various systems. [ 128–130 ] For examples, S a values that independent of dopant concentration were observed in Er 3+ /Yb 3+ codoped phosphors, such as Na 0.5 Gd 0.5 MoO 4 , Ba 5 Gd 8 Zn 4 O 21 and BiOCl. [ 56,76,131 ] However, the reductions in FIR and S a values in fluorotellurite glass were reported as increasing the Er 3+ concentration.…”

Eulytite-type Ba3Yb(PO4)3:Tm/Er/Ho as a high sensitivity optical thermometer over a broad temperature range

“…As shown in Fig. the relationship between FIR and temperature T can be accurately described by eqn (7), yielding a high fitting correlation of R 2 = 99.9%. The calculated values for B and DE/K are 8.652 and 1042.241, respectively.…”

“…8c, FIR Er/Tm (n-TCELs) was fitted using eqn (3), FIR Er1 (TCELs) was fitted using eqn (6), and FIR Er/Ho (n-TCELs) was fitted using eqn (9). Correspondingly, the S r and S a values of FIR Er/Tm were calculated using eqn (4) and ( 5), FIR Er1 was calculated using eqn (7) and ( 8), and FIR Er/Ho was calculated using eqn (10) and (11), as shown in Fig. 8d and Fig.…”

“…3,4 However, designing an optical thermometer with high sensitivity over a wide temperature range remains a challenging task. [5][6][7] UC luminescent materials based on rare earth ion doping have important application prospects in the field of optical temperature measurement. [8][9][10][11] Selecting suitable host materials is one of the key factors in achieving efficient and stable optical thermometers.…”

Luminescence of Mn4+ in a Zero-Dimensional Organic–Inorganic Hybrid Phosphor [N(CH3)4]2ZrF6 for Dual-Mode Temperature Sensing

“…Meanwhile, the narrow emission of Mn 4+ consists of some vibronic transitions due to an 2 E g – 4 A 2g transition, which can be regarded as thermally coupled vibronic levels. Hence, Mn 4+ doped fluoride phosphor is an excellent candidate for applications in fluorescence thermometers [ 18 , 19 , 20 , 21 , 22 , 23 , 24 ]. Recently, zero-dimensional organic inorganic phosphors have attracted unparalleled interest owing to their unique crystallographic structures with fascinating optical characteristics [ 25 ].…”