Synthesis of hollow La2O3:Yb3+/Er3+/Tm3+ microspheres with tunable up-conversion luminescence properties

Abstract

Tm 3+ ) microspheres were successfully synthesized via a facile sacrificial template method by employing PS spheres as hard template followed by a subsequent heating process. The structure, morphology, and formation process are well investigated by various techniques. A systematic study on the up-conversion (UC) PL properties of La 2 O 3 :Yb 3+ /Er 3+ /Tm 3+ products have been performed in detail. Under 980 nm laser diode excitation, La 2 O 3 :Yb 3+ /Tm 3+ , La 2 O 3 :Er 3+ and La 2 O 3 :Yb 3+ / Er 3+ products are mainly dominated by blue, green, and red light emissions, respectively. By increasing Er 3+ concentration, the La 2 O 3 :Er 3+ gives yellow emission. Furthermore, the UC white light was successfully obtained in the La 2 O 3 :Yb 3+ /Er 3+ /Tm 3+ system by adjusting the relative doping concentration of Yb 3+ , Er 3+ and Tm 3+ . The obtained UC white light can be tuned at a wide range, and the optimal white-emitting CIE (Commission internationale de l'e ´clairage [International Commission on Illumination]) chromaticity coordinate is (x = 0.3250, y = 0.3180), which is very close to the standard equal energy white light (x = 0.33, y = 0.33). The strategies for color tuning of up-conversion emission proposed in the current system may be helpful for other ones to achieve efficient multicolor (including white light) luminescence under 980 nm laser excitation. Because of abundant luminescent colors from RGB to white in La 2 O 3 :Yb 3+ /Er 3+ / Tm 3+ samples under 980 nm laser diode (LD) excitation, they can potentially be used as fluorophores in the field of color displays, back light, UC lasers, and photonics.

Facile synthesis of hollow microspherical YPO 4 : Eu 3+ /Tb 3+ using polystyrene spheres as sacrificial template and its photoluminescent properties

“…The as‐obtained PS spheres show a diffraction peak at 19° (Fig. 1 (a)) [13, 40]. The urea‐assisted homogeneous precipitation product (PS@Y(OH)CO 3 ) shows two bands at 30° and 47° (Fig.…”

Lanthanide‐doped hollow nanomaterials as theranostic agents

“…Last step is calcination process, which has a dual function: the removal of carbon spheres cores and formation of hollow crystalline structures from Ln(OH)CO 3 melamine formaldehyde) are also applied for the fabrication of hollow spheres. [24][25][26]28,29,30 Tube is also a form of hollow architecture. Zhao et al synthesized NaYF 4 nanotube arrays by using the anodic aluminum oxide (AAO) as the template (Figure 1(II)(d)).…”

“…Last step is calcination process, which has a dual function: the removal of carbon spheres cores and formation of hollow crystalline structures from Ln(OH)CO 3 precursor layer. Besides carbon spheres, other hard templates (polystyrene, silica spheres, and melamine formaldehyde) are also applied for the fabrication of hollow spheres –,, , …”

Synthesis and luminescent properties of uniform monodisperse LuPO 4 :Eu 3+ /Tb 3+ hollow microspheres

“…Furthermore, to the best of our knowledge, the properties of rare earth luminescent micro/nanomaterials have a strong dependence on their chemical composition, size, morphology and crystallinity [8–13]. Therefore, regulating and controlling the size, shape and morphology of rare earth luminescent micro/nanomaterials are the focuses of chemistry and materials science [14,15].…”