Investigation of Upconversion Photoluminescence of Yb³⁺/Er³⁺:NaLaMgWO₆ Noncytotoxic Double-Perovskite Nanophosphors

Abstract

Bright fluorescent rare-earth-ion-doped upconversion nanomaterials are attractive choices for photonic devices. A remarkable green upconversion emission has been obtained by the sensitizing effect of Yb 3+ in a Yb 3+ /Er 3+ :NaLaMgWO 6 (NLMWO) nanophosphor under near-infrared (NIR) excitation. A citrate sol−gel method was employed to synthesize the nanophosphor samples. The lack of a secondary phase in the X-ray diffraction pattern confirms that the Er 3+ and Yb 3+ ions are incorporated in the ordered double-perovskite structure. Surface analysis and particle evaluation are performed by field-emission scanning electron microscopy and transmission electron microscopy analysis. Upconversion and downconversion emission performances were systematically studied by varying the dopant concentrations. A strong upconversion green emission can be observed with the naked eye, and it resembles the upconversion spectra of Er 3+ -doped phosphors. Remarkably, because of an energy-transfer process, the green upconversion emission can be converted into a strong red emission by codoping with Yb 3+ ions. We observed the color tuning effect from green to red, which can be controlled by varying the Yb 3+ concentration in the codoped phosphors during NIR excitation. A systematic investigation of the upconversion mechanism from Yb 3+ to Er 3+ doubly doped NLMWO nanocrystals is demonstrated. The upconversion mechanism was evaluated only by varying the excitation power of the laser as well. A strong NIR emission at 1.57 μm corresponding to Er 3+ can be significantly enhanced by increasing the codoping concentration of Yb 3+ ions. The energy migration pathway is accurately presented. The Commission internationale de l'ećlairage color coordinates were analyzed for singly and doubly doped nanophosphors. The cytotoxicity of the codoped nanophosphor system was evaluated using WI-38 cell lines. This optimized codoped nanophosphor material is noncytotoxic; thus, it can be useful for in vitro studies in biological studies. On the basis of the obtained results, the NLMWO:Yb 3+ /Er 3+ nanophosphors can be a promising choice for novel upconversion photonic applications.

Multimodal Luminescent Yb3+/Er3+/Bi3+‐Doped Perovskite Single Crystals for X‐ray Detection and Anti‐Counterfeiting

“…Until recently, RE doped double perovskite materials are reported with UC phenomenon. [ 49,50 ] In our work, it is noted that the Yb 3+ /Er 3+ co‐doped samples RE‐1, RE‐2, and RE‐3 emit UC PL of Yb 3+ /Er 3+ ions (Figure 2g). Under the excitation of NIR laser (980 nm), the three Yb 3+ /Er 3+ co‐doped samples all emit three characteristic peaks of Er 3+ at 527 nm, 555 nm, and 660 nm, and the corresponding energy level transitions are 2 H 11/2 → 4 I 15/2 , 4 S 3/2 → 4 I 15/2 , and 4 F 9/2 → 4 I 15/2 , respectively.…”

“…[ 20 ] As known, most of the matrices for RE‐based UC materials are oxides or fluorides, in which DS PL is rarely achievable. [ 21 ] For DS materials like quantum dots, doping RE ions is rather difficult. [ 22 ] And it is also difficult to combine organic molecules with RE ions to simultaneously realize UC and DS PL.…”

Luminescence Properties of Rare Earth–Doped Cubic Double Perovskite Tungstate Ba2(1−x)(Na,RE)xZnWO6 (RE = Ce3+, Eu3+ and Dy3+) Phosphors

“…[1][2][3][4][5][6][7][8][9] Recently, perovskite materials have gained more attention for their noteworthy application in photovoltaic [6] and perovskite light-emitting diodes (LEDs). [3,4] This family of materials has proven to be the best for doping of transition metal ions [9,10] as well as rare earth ions [7,8,[11][12][13] for the enhancement of physical properties for various applications. Nevertheless, rare earth ions are preferred over transition metal ions as dopants in perovskite host lattices due to the very peculiar spectroscopic characteristics required for developing a good phosphor.…”

Facile Realization of Boosted Near‐Infrared‐Visible Light Driven Photocatalytic Activities of BiOF Nanoparticles through Simultaneously Exploiting Doping and Upconversion Strategy

“…[18] Furthermore, the symmetric peak at 183.9 eV is associated with the Er 3+ 4d 5/2 , whereas the band centered at 197.6 eV belongs to the Yb 3+ 4d 5/2 (see Figure 3d). [37] These XPS results further indirectly testify that the dopants of Er 3+ and Yb 3+ ions are successfully incorporated into the BiOF host lattices.…”