Ultra-broad near-infrared photoluminescence from crystalline (K-crypt)2Bi2 containing [Bi2]2− dimers

Luminescent metal nanoclusters: controlled synthesis and functional applications

“…Bi coordinates with Bi element itself). The charges that such clusters possess can be balanced by other structural units such as [AlCl 4 ] − or [K-crypt] + (Crypt = 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8] hexacosane) [41–45]. Indeed, the study of such peculiar subnanometer Bi NCs dates back to half a century ago.…”

“…In addition to molecular crystals containing Bi polycations, it is noteworthy that many compounds with Bi polyanions absorb light in the visible range of the electromagnetic spectrum since they are colored, thus giving promise for unique optical properties [45]. In 2012, Sun and coworkers first reported that a single crystal of (K-crypt) 2 Bi 2 which contains [Bi 2 ] 2− polyanions displays ultrabroad NIR emission at around 1190 nm (figure 11).…”

“…In 2012, Sun and coworkers first reported that a single crystal of (K-crypt) 2 Bi 2 which contains [Bi 2 ] 2− polyanions displays ultrabroad NIR emission at around 1190 nm (figure 11). As demonstrated in figure 11(b), the emission spectrum under 641 nm excitation has a very broad emission range, spanning from 975 to 1400 nm [45]. The full width at half maximum (FWHM) of the spectrum is 212 nm and the emission peak is around 1190 nm.…”

“…In recent years, employing state-of-the-art quantum chemistry codes, relatively accurate prediction and explanation of the optical properties of a broad range of NCs have been realized [8–12]. A broad range of luminescent metal NCs composed of gold (Au) [5–7, 13–27], silver (Ag) [12, 25–36], copper (Cu) [25, 35, 37, 38], platinum (Pt) [25, 39, 40], bismuth (Bi) [11, 41–45], molybdenum (Mo) [46–48] or mixed metals [49–51] have been successfully fabricated using diverse top-down or bottom-up approaches. Compared with other counterparts, Au and Ag NCs have attracted more attention and have been intensively studied over the past decade.…”

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

“…[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.…”