Down shifting and quantum cutting from Eu³⁺, Yb³⁺ co-doped Ca₁₂Al₁₄O₃₃ phosphor: a dual mode emitting material

Abstract

We report the quantum cutting (QC) in a Eu3+, Yb3+ co-doped Ca12Al14O33 phosphor synthesized through combustion method.

Strategy to probe multimodal light emissions from Eu3+/Yb3+activated garnet nanophosphors for LED devices and solar cell applications

“…23 Another advantage of such a scheme of energy levels of Tb 3+ /Eu 3+ and Yb 3+ is that they can give QC emission from Yb 3+ via 2 F 5/2 → 2 F 7/2 transition under UV excitation, and this QC emission occurs via the CET from the single Tb 3+ /Eu 3+ ion to a pair of Yb 3+ ions. 24 It is beneficial to observe the QC emission from Yb 3+ in the spectral region of about 950–1050 nm as this region matches well with the absorption spectrum of c-Si solar cells, and thus, Tb 3+ /Yb 3+ or Eu 3+ /Yb 3+ co-doped phosphors could enhance the photovoltaic performances. This type of QC emission was first observed in a Yb 3+ /Pr 3+ co-doped fluoride-based host 25 and later it was explored in Yb 3+ /Tm 3+ , 26 Yb 3+ /Nd 3+ , 27 Yb 3+ /Tb 3+ (ref.…”

“…Among these transitions, the intensities of the emission bands corresponding to 5 D 0 → 7 F 1 (related to the magnetic dipole moment) and 5 D 0 → 7 F 2 (related to the electric dipole moment) transitions follow a diverse trend in different host matrices and so their asymmetric ratio, that is 5 D 0 → 7 F 1 / 5 D 0 → 7 F 2 could be used to predict the symmetric site of Eu 3+ . 17,24,38 According to the Judd–Ofelt spin parity rule, transitions of Eu 3+ caused by a magnetic dipole moment are allowed but are not allowed for the electric dipole moment. However, this spin forbidden transition law will no longer be valid when Eu 3+ occupies low centrosymmetric sites.…”

“…28) co-doped systems. However, QC emission from Eu 3+ /Yb 3+ has been explored in very few hosts for example Luo et al , 29 and Yadav et al , 24 have inspected it in fluorosilicate glass and a Ca 12 Al 14 O 33 phosphor, respectively.…”

Enhanced Quantum Cutting via Li+ Doping from a Bi3+/Yb3+-Codoped Gadolinium Tungstate Phosphor

“…The pure Bi 3+ -doped sample does not show any absorption band in the NIR region. However, when Yb 3+ is added to the Bi 3+ -doped sample, the spectra show a band at 976 nm, which is due to the 2 F 7/2 → 2 F 5/2 transition of the Yb 3+ ion and is shown as an inset in the figure. The presence of Li + ion in the sample significantly enhances the intensity of the absorption bands, which results in better emission intensity of the codoped sample.…”

Characterization of Luminescent Down-Shifting Spectral Conversion Effects on Silicon Solar Cells with Various Combinations of Eu-Doped Phosphors

“…LDS and DC spectral conversion layers improve the responsivity of C-Si solar cells operating at shorter wavelengths while reducing recombination loss and thermalization loss. Lanthanides are used extensively in spectral conversion due to their rich energy-level configuration, which facilitates photon management [21,22]. Europium-doped (Eu-doped) phosphors are ideally suited to LDS, owing to their high luminescent quantum yield and large Stokes shift [23][24][25].…”