Fluorescence resonance energy transfer of CaF 2 : Eu 2+ , Tb 3+ applied to dye-sensitized solar cells

Energy Transfer between Tb3+ and Eu3+ in LaPO4: Pulsed versus Switched‐off Continuous Wave Excitation

“…The mechanism of ET between Tb 3+ and Eu 3+ has been previously studied with conflicting results, which claimed that ED–ED, ED–EQ, or exchange is the dominant interaction mechanism. Naturally, the mechanism may depend upon the crystal structure, determining the site symmetries of these ions and the distance between them.…”

“…For example, Moran et al studied the cubic system Cs 2 NaYCl 6 doped with Tb 3+ and Eu 3+ in a wide range of concentrations at 298 and 77 K. It was concluded that discrepancies between the calculated and experimental rate parameters are large, notably by four or five orders of magnitude for multipole–multipole mechanisms. Whereas it could be possible that different interaction mechanisms take part in different solid‐state lattices, various studies have attributed the interaction mechanism between Tb 3+ and Eu 3+ to electric dipole–electric dipole (ED–ED), or electric dipole–electric quadrupole (ED–EQ) or exchange interaction . The 5 D 4 → 7 F j ( J = 6‐4) transitions of Tb 3+ are forced ED allowed whereas the 5 D 0 ← 7 F 0 transition of Eu 3+ is dipole forbidden, but at room temperature the 5 D 0 ← 7 F 1 forced ED pathway is also available.…”