NIR Downconversion and Energy Transfer Mechanisms in Tb³⁺/Yb³⁺ Codoped Na₅Lu₉F₃₂ Single Crystals

Abstract

Tb/Yb codoped NaLuF single crystals with near-infrared (NIR) emission are achieved by an improved Bridgman approach. Energy transfer from Tb to Yb ions is affirmed by the photoluminescence (PL) emission spectra and decay curves characterization. On the basis of the analysis of energy transfer rate dependence on the Yb concentration, the interaction between Tb and Yb ions in NaLuF single crystals is confirmed through the one-to-one energy transfer process. Results demonstrate that the prepared NaLuF single crystals might be promising candidates to convert sunlight to improve the performance of the silicon solar cells.

Devitrification Behavior of Sol-Gel Derived ZrO2-SiO2 Rare-Earth Doped Glasses: Correlation between Structural and Optical Properties

“…Typically, the Tb→Yb cooperative energy transfer is considered to be the most probable relaxation pathway from the 5 D 4 excited state of the Tb 3+ ion since the probability of the non-radiative multi-phonon relaxation needed to compensate the energy gap between the 5 D 4 (Tb 3+ ) and 3 F 5/2 (Yb 3+ ) excited states, is small. In some materials the one-to-one energy transfer mechanism can dominate over the down-conversion process [33]. As was mentioned above, the concentration of the REE in the t-ZrO 2 crystalline phase decreased significantly when compared to the pristine glass, i.e., the possibility of finding an Yb-Yb pair in the nearest sphere of Tb 3+ is much smaller.…”

The effects of dopant concentration and excitation intensity on the upconversion and downconversion emission processes of β-NaYF4:Yb3+,Er3+ nanoparticles

“…28,29 UCNPs not only show upconversion luminescence (UCL), but they have even more efficient downconversion luminescence (DCL) in the near infrared (NIR) which make them ideal candidates for NIR to NIR-DC bioimaging applications. 30,31 Interestingly it has also been reported that UCL and DCL emission depend on the size of the NaYF 4 :Yb 3+ ,Er 3+ nanoparticles. UCL intensity increase as the nanoparticles' size increases, whereas in DCL, the most efficient emission occurs for diameters ranging from 15nm to 40 nm when high excitation intensities are used.…”

Advances in Near-Infrared Luminescent Materials without Cr3+: Crystal Structure Design, Luminescence Properties, and Applications

“…The main energy transfer is Ln → Yb 3+ /Er 3+ /Tm 3+ (Ln: Eu 2+ , Ce 3+ , Tb 3+ , Yb 3+ , Er 3+ , Tm 3+ ). 290 Among them, Ln ions mainly absorb n-UV or blue light. Because the excited energy of Ln is much higher than that of Yb 3+ /Er 3+ /Tm 3+ ions, there are two energy transfer channels from the excited level of Ln ions to that of the Yb 3+ /Er 3+ /Tm 3+ ion.…”

“…In quantum-cutting NIR luminescent materials, energy transfer is indispensable. The main energy transfer is Ln → Yb 3+ /Er 3+ /Tm 3+ (Ln: Eu 2+ , Ce 3+ , Tb 3+ , Yb 3+ , Er 3+ , Tm 3+ ) . Among them, Ln ions mainly absorb n-UV or blue light.…”