Luminescence–structure relationships in solids doped with Bi³⁺

Abstract

The luminescence properties of Bi3+ in 177 inorganic compounds are reviewed and rationalized based on two simple and easy-to-use models. These models are applicable to any kind of compound whose...

Unraveling the origin of broadband yellow emission in Bi3+-doped LuXnGaO4 (Xn = Mg, Zn) phosphors

“…Currently, the origin of the extra-ionic electronic transition of Bi 3+ is commonly attributed to either the formation of Bi 3+ pairs or to an MMCT transition. 1,28–32 To elucidate the origins of the excitation peaks in LuXnGaO 4 :Bi 3+ (Xn = Zn, Mg), the semi-empirical models proposed by Philippe Boutinaud were employed to predict the energies of Bi 3+ pairs, MMCT and 1 S 0 → 3 P 1 transitions. 1,30,31 The Bi 3+ pair/cluster model proposes that Bi 3+ has an electronic configuration of 6s 2 , allowing adjacent Bi 3+ ions to form ion pairs.…”

“…This leads to LuXnGaO 4 :Bi 3+ emission arising from the Bi 3+ pair transition. To further determine the origin of LuXnGaO 4 :Bi 3+ emission, a criterion was introduced based on the energy difference between the calculated values of the extra-ionic transition ( E e ), intra-ionic transition ( E a ) and Stokes shift ( S ), as follows: 31 Δ E (Bi 3+ ) = | E e − E a − S |.…”

“…1,28–32 To elucidate the origins of the excitation peaks in LuXnGaO 4 :Bi 3+ (Xn = Zn, Mg), the semi-empirical models proposed by Philippe Boutinaud were employed to predict the energies of Bi 3+ pairs, MMCT and 1 S 0 → 3 P 1 transitions. 1,30,31 The Bi 3+ pair/cluster model proposes that Bi 3+ has an electronic configuration of 6s 2 , allowing adjacent Bi 3+ ions to form ion pairs. 30–32 The overlap of Bi 3+ pair orbitals generates low-energy excited state levels, leading to a long-wavelength emission with a broad band and large Stokes shift.…”

“…1,30,31 The Bi 3+ pair/cluster model proposes that Bi 3+ has an electronic configuration of 6s 2 , allowing adjacent Bi 3+ ions to form ion pairs. 30–32 The overlap of Bi 3+ pair orbitals generates low-energy excited state levels, leading to a long-wavelength emission with a broad band and large Stokes shift. The previous structural analysis also provides a foundation for the existence of Bi 3+ pairs in LuXnGaO 4 :Bi 3+ .…”

“…The energy of 1 S 0 → 3 P 1 transition ( E sp ) can be predicted using the following empirical equations: 31 E sp (Bi 3+ ) = E A (1 − Kh e α ),where E f is the energy of the 1 S 0 → 3 P 1 transition of Bi 3+ in the free ion, K and α are phenomenological parameters, h e is the ligand's capacity to induce orbital expansion of the central ion, f c (M–Xi) and α (M–Xi) are the fractional covalency and the volume polarization of each chemical bond that separates the cation M to its nearest ligands Xi, respectively, and Q (Xi) is the charge of the anion Xi. The calculation methods for variables f c (M–Xi), α (M–Xi) and Q (Xi) can be referred from ref.…”