Subvalent bismuth monocation Bi+ photoluminescence in ternary halide crystals KAlCl4 and KMgCl3

Near infrared photoluminescence of the univalent bismuth impurity center in leucite and pollucite crystal hosts

“…This implies the similar nature of emissive centers for all observed NIR luminescence spectral diapasons. Also, the characteristic decay time of NIR luminescence is similar to the other crystal phases, 18 The crystal field of low symmetry in the disordered pollucite lattice splits all the degenerate levels and the lowest energy component from the 3 P 1 manifold forms the level, from which the main radiative transition to the ground state had occurred, causing NIR luminescence. Due to the disordered crystal lattice, the Bi + population is heterogeneous -situated in different crystal environments with varying crystal field strengths.…”

“…Since the discovery of the broadband near-infrared (NIR) photoluminescence from bismuth doped glasses [1][2][3][4][5] and crystalline materials [6][7][8][9][10][11][12][13][14][15][16][17][18][19] the nature of corresponding luminescent species is widely discussed. The Bi 3+ ion in the common oxidation state +3 has no optical transitions in NIR and the observed emission was attributed to possible Bi 5+ , 1 Bi 2+ , 20 Bi + , 21 Bi 0 , 8,9,22 Bi 2 À , Bi 2 2À , 23 and bismuth cluster species.…”

“…[29][30][31][32][33] It is interesting that NIR luminescence has also been detected from the bismuth dimer anion (Bi 2 2À ) in the (K-crypt) 2 Bi 2 crystal phase. 34 It was also demonstrated that the univalent bismuth cation (Bi + ) is the NIR emitter in the ternary halide crystals KAlCl 4 , KMgCl 3 , RbPb 2 Cl 5 , and CsCdCl 3 , 14,17,18,35,36 where Bi + substitutes isomorphically for the large alkali cations. On the other hand, it seems that several different emitters contribute to the net NIR photoluminescence in Bi-doped SiO 2 and GeO 2 -based glasses.…”

“…The spectra of NIR photoluminescence, luminescence excitation and 2D excitation-emission spectra along with photoluminescence kinetic characteristics were obtained at room temperature as described earlier. 17,18,35,36 Several CW diode and DPSS lasers with wavelengths of 405 nm, 470 nm, 532 nm, 635 nm, 660 nm and 690 nm and 20-200 mW output power were employed to excite the photoluminescence.…”

Influence of monovalent Bi+ doping on real composition, point defects, and photoluminescence in TlCdCl3 and TlCdI3 single crystals

“…The unit cell parameters of TlCdI 3 :Bi single crystals, determined by both XRD and SCXRD analyses (Table 1), are smaller than those found for the undoped TlCdI 3 crystals [30]. It follows that the Tl + ions (r Tl VIII = 1.59 Å [31]; r is a cation radius) are not replaced by the Bi + ones (r Bi VIII = 1.774 Å [12]), as was supposed [17,[32][33][34][35][36][37][38]. The refinement of the Tl site occupancy showed its decrease, which also evidences an absence of the Bi + ions in this site (the form factor or atomic factor is proportional to the atomic number), but indicates the presence of vacancies ( Table 1).…”