Remarkable differences in photoluminescent properties between LaPO4:Eu one-dimensional nanowires and zero-dimensional nanoparticles

Abstract

Photoluminescent properties of zero-dimensional LaPO4:Eu nanoparticles (NPs) and one-dimensional nanowires (NWs) prepared by the same wet-chemical synthesis technique were studied and compared. The results indicate that in NP Eu3+ occupied only one site, A, while in NW Eu3+ occupied the same site, A and an additional site B due to crystal anisotropy. Furthermore, the electronic transition rate of D15–∑JFJ7 in the NW increased from 14.9to28.9ms−1 compared to the NP, while the nonradiative transition rate of D15–D05 decreased from 24.1to19.7ms−1. The luminescent quantum efficiency thus improved from 30% to 59%. This work demonstrates that a one-dimensional NW may be a more favorable device than a zero-dimensional NP for photoluminescence.

ZnWO4:Eu3+ nanorods: A potential tunable white light-emitting phosphors

“…4 presents a series PL spectra of ZnWO 4 :xEu 3+ (x = 0, 0.1, 0.5, 1, 2, 3, 5 mol.%) nanorods prepared at pH = 6 with the reaction temperature of 180 • C. It can be seen clearly that the emission intensity of blue-green band decreases gradually with increasing Eu 3+ concentration from 0 to 3 mol.%. Meanwhile, the emission intensity of Eu 3+ exhibits the opposite tendency, which confirms the efficient energy transfer process from WO 4 2− to Eu 3+ . However, the emission intensity of tungstate group increases and Eu 3+ decreases again when the concentration of Eu 3+ reaches 5%, due to concentration quenching [27].…”

“…The lifetime is determined to be 17.5 and 15.4 s for ZnWO 4 and ZnWO 4 :0.1% Eu 3+ nanorods, respectively. The shortening lifetime of ZnWO 4 :0.1% Eu 3+ is a further evidence for the energy transfer from WO 4 2− to Eu 3+ in ZnWO 4 host. Following the available CIE (Commission International de L'Eclairage, France, 1931) standard, we computed the CIE chromaticity coordinates (x, y) of ZnWO 4 :Eu 3+ phosphors and are marked as points a, b, c, d, e, f and g in Fig.…”

“…One-dimensional lanthanide-doped nanomaterials have attracted extensive attention in luminescence devices, displays, biolabeling and other functional materials owing to their electronic, optical and chemical properties originated from the 4f shell of rare earth ions [1][2][3][4]. Especially for high-performance Eu 3+ -doped phosphor, this is a key component for tri-color luminescence in various devices to realize white light.…”

“…Upon excitation at 282 nm, the charge transfer of O 2− → W 6+ firstly happens and emits bluegreen light extending from 380 to 580 nm. On the other hand, efficient energy transfer from WO4 2− to 4f shell of Eu 3+ occurs. Thus, the electrons of Eu 3+ at 5 D 0 excited state can populate both from the nonradiative charge transfer feeding and the 5 D J → 5 D 0 relaxation, then emit the characteristic red light at 577, 590, 613 and 624 nm corresponding to the 5 D 0 → 7 F J (J = 0-3) transitions, respectively.…”

Structural and photoluminescence properties of europium-doped titania nanofibers prepared by electrospinning method

“…Rare earth compounds have been widely used as high-performance luminescent devices, magnets, catalysts, and other functional materials [5,6]. It has been reported that the luminescent quantum efficiency of Eu 3+ in nanowires was enhanced more considerably than that of the corresponding nanoparticles and the bulk powders [7]. Some wide band-gap semiconductors including Y 2 O 3 [8], AlN [9], GaN [10], ZnO [11], TiO 2 [12] have been selected as host materials in order to excite rare earth ions efficiently and to yield intense luminescence.…”