Infrared‐to‐Visible Light Conversion in Er³⁺–Yb³⁺:Lu₃Ga₅O₁₂ Nanogarnets

Abstract

Er(3+) -Yb(3+) co-doped Lu3 Ga5 O12 nanogarnets were prepared and characterized; their structural and luminescence properties were determined as a function of the Yb(3+) concentration. The morphology of the nanogarnets was studied by HRTEM. Under 488 nm excitation, the nanogarnets emit green, red, and near-infrared light. The decay curves for the ((4) S3/2 , (2) H11/2 ) and (4) F9/2 levels of the Er(3+) ions exhibit a non-exponential nature under resonant laser excitation and their effective lifetimes are found to decrease with an increase in the Yb(3+) concentration from 1.0 to 10.0 mol %. The non-exponential decay curves are well fitted to the Inokuti-Hirayama model for S=8, indicating that the mechanism of interaction for energy transfer between the optically active ions is of dipole-quadrupole type. Upon 976 nm laser excitation, an intense green upconverted emission is clearly observed by the naked eyes. A significant enhancement of the red-to-green intensity ratio of Er(3+) ions was observed with an increase in Yb(3+) concentration. The power dependence and the dynamics of the upconverted emission confirm the existence of two-photon upconversion processes for the green and red emissions.

Stokes and anti-Stokes luminescence in Tm3+/Yb3+-doped Lu3Ga5O12 nano-garnets: a study of multipolar interactions and energy transfer dynamics

“…The lattice parameter is more or less similar upon substitution of ions. 14 A slight change in the unit cell parameter with dopant concentration can be ascribed to the changes in the position of oxygen ions since the oxygen ion can be easily polarizable due to its relatively low electron density and size. The higher concentration of Ln 3+ ions leads to higher deformation of the oxygen ions.…”

“…4,[9][10][11][12] Among different kinds of oxide host matrices, garnets are important due to their fascinating physical, chemical, and optical properties. 13,14 Especially, lutetium (Lu) based garnets are advantageous because top of the valence band is mainly composed of 4f [Lu] orbitals. 15 Therefore, the luminescence of Ln 3+ ions in Lu based crystals would increase according to the intensity-borrowing mechanism.…”

Rare Earth Ion Doped Luminescent Materials: A Review of Up/Down Conversion Luminescent Mechanism, Synthesis, and Anti-Counterfeiting Application

“…However, some luminescent materials also exhibit Anti-Stokes luminescence, where the excitation wavelength is greater than the emission wavelength. Anti-Stokes luminescence is a special optical process that can convert two or more low-energy photons into one high-energy photon and emit it [37][38][39][40][41][42][43]. The unique performance is due to the existence of some long-lived excited state intermediate levels of light-emitting ions, so that light absorption does not start from ground state, but transitions from the intermediate level to a higher excited state level.…”

Crystalline Phase, Cross-Section, and Temporal Characteristics of Erbium-Ion in Lu3Ga5O12 Crystal

“…In recent years, studies have been performed on several lanthanide-/transition metal-doped LuGG single crystals or polycrystalline powders. The dopants concern the ions erbium [1][2][3][4][5], ytterbium [5][6][7][8][9][10], chromium [11], samarium [12], holmium [13], neodymium [14], and bismuth [15].…”