Luminescence Spectroscopy and Origin of Luminescence Centers in Bi-Doped Materials

Abstract

Bi-doped compounds recently became the subject of an extensive research due to their possible applications as scintillator and phosphor materials. The oxides co-doped with Bi3+ and trivalent rare-earth ions were proposed as prospective phosphors for white light-emitting diodes and quantum cutting down-converting materials applicable for enhancement of silicon solar cells. Luminescence characteristics of different Bi3+-doped materials were found to be strongly different and ascribed to electronic transitions from the excited levels of a Bi3+ ion to its ground state, charge-transfer transitions, Bi3+ dimers or clusters, radiative decay of Bi3+-related localized or trapped excitons, etc. In this review, we compare the characteristics of the Bi3+-related luminescence in various compounds; discuss the possible origin of the corresponding luminescence centers as well as the processes resulting in their luminescence; consider the phenomenological models proposed to describe the excited-state dynamics of the Bi3+-related centers and determine the structure and parameters of their relaxed excited states; address an influence of different interactions (e.g., spin-orbit, electron-phonon, hyperfine) as well as the Bi3+ ion charge and volume compensating defects on the luminescence characteristics. The Bi-related luminescence arising from lower charge states (namely, Bi2+, Bi+, Bi0) is also reviewed.

Origin of Luminescence in Sb3+- and Bi3+-Doped Cs2SnCl6 Perovskites: Excited State Relaxation and Spin–Orbit Coupling

“…Owing to their interesting optical absorption and emission properties, ns 2 -ions have been lattice-doped in a wide variety of hosts such as alkali halides, 15−20 metal oxides, 21−23 and zeolites. 24 The ground state of an ns 2 -ion is 1 S 0 , and the excited states are 1 P 1 and 3 P n (n=0, 1, 2) , as shown in Figure 1a. The diagonal matrix elements of spin−orbit coupling split 3 P into 3 P 0 , 3 P 1 , and 3 P 2 .…”

“…Metal ions such as In + , Ga + , Tl + , Ge 2+ , Sn 2+ , Pb 2+ , Sb 3+ , and Bi 3+ have ns 2 electrons in the outermost orbitals and are often termed as ns 2 ions. Owing to their interesting optical absorption and emission properties, ns 2 -ions have been lattice-doped in a wide variety of hosts such as alkali halides, − metal oxides, − and zeolites . The ground state of an ns 2 -ion is 1 S 0 , and the excited states are 1 P 1 and 3 P n ( n =0, 1, 2) , as shown in Figure a.…”

Dual‐Band‐Tunable White‐Light Emission from Bi3+/Te4+ Emitters in Perovskite‐Derivative Cs2SnCl6 Microcrystals

“…in Cs 2 NaBiCl 6 and Cs 2 NaLaCl 6 : Bi 3+ crystals [13] . This suggests that the 3 P 1 state of Bi 3+ locates well below the host conduction band, which favors the isolated Bi 3+ emission from the 3 P 0,1 levels [12a] . From Tauc plots of the diffuse reflectance spectra (Figure S12), the optical band gaps were estimated to be 4.12, 3.97, 3.96, and 3.95 eV for Cs 2 SnCl 6 : x %Bi 3+ MCs with 0, 0.2, 1.1, and 1.4 mol% of Bi 3+ , respectively, indicating that the Bi 3+ 6p orbital may alloy to the host conduction band and lower the band gap energy.…”

The Application of Bi‐Doped TiO2 for the Photocatalytic Oxidation of Formaldehyde

“…Impurity doping can improve the performance of the catalyst in two ways: reducing the bandgap of the material to reduce the energy required for electron transition, alternatively, reducing the recombination velocity of carriers by forming traps. [ 26 ] In this paper, the doping of bismuth improves the photocatalytic performance by the former way.…”