Recent Advances in Super Broad Infrared Luminescence Bismuth-Doped Crystals

Abstract

Summary Bismuth (Bi)-doped materials are capable of exhibiting broadband near-infrared (NIR) luminescence in 1,000–1,700 nm; driven by the potential use in lasers and broadband optical amplifiers for modern fiber communication systems, Bi-activated NIR luminescencent glasses and related devices have attracted much attention. Compared with glass systems, Bi-doped crystals as gain media usually have more regular crystal structures to produce stronger NIR signals, and developing such materials is highly desirable. Regarding the recent advances in Bi-doped NIR crystals, here, for the first time, we summarized such crystals listed as two main categories of halogen and oxide compounds. Then, by comparing the substitution site, coordination environment, emission and excitation luminescence peaks, emitting center species, and decay times of these known Bibased NIR crystals, discussion on how to design Bi-doped NIR crystals is included. Finally, the key challenges and perspectives of Bi-doped NIR crystals are also presented. It is hoped that this review could offer inspiration for the further development of Bi-doped NIR luminescent crystals and exploit its potential applications.

Li/Na substitution and Yb3+ co-doping enabling tunable near-infrared emission in LiIn2SbO6:Cr3+ phosphors for light-emitting diodes

“…Unfortunately, single invisible fluorescence emissions of Eu 2+ , Mn 2+ , and Fe 3+ ions are hard to acquire, and their emissions FWHM are insufficient ( Berezovskaya et al., 2013 ; Song et al., 2015 ; Zhou et al., 2020 ). Although Ni 2+ and Bi ion-activated crystal or glass materials usually exhibit an ultra-broadband emission in the second NIR window (NIR-II, 1000-1700 nm), their luminous efficiency is disappointed ( Cao et al., 2018 ; Xiong et al., 2020 ). On the contrary, Cr 3+ ion has been considered as an ideal NIR luminescence center in view of its high quantum efficiency and tunable emission spectrum in 650-1600 nm which strongly depends on the crystal field strength ( Bai et al., 2018 ).…”

Regulating the Bi NIR luminescence behaviours in fluorine and nitrogen co-doped germanate glasses

“…As far as we know, the Bi activate centers are highly sensitive to the variation of the local crystal field and glass structures around them. [43][44][45] To reveal the deeper mechanism behind what we have discussed above, structure analysis by FTIR and EPR have been performed to offer more detailed information concerning the relationship between the microstructure of the glasses and the optical properties of Bi activate NIR centers. FTIR spectra is illustrated in Fig.…”

Visible and Near-Infrared Emission in Ba3Sc4O9:Bi Phosphor: An Investigation on Bismuth Valence Modification

“…Bismuth (Bi)-activated materials have been researched extensively over the past decades for their potential applications in fields of biomedical, lighting, and optical fiber communication. − As a nontoxic and versatile heavy metal element, the tunable emission of Bi is closely associated with its abundant complexation states and redox in certain compounds. For instance, CaYGaO 4 :Bi 3+ , Ba 2 Y 5 B 5 O 17 :Bi 3+ , Y 3 Al 2 Ga 3 O 12 :Bi 3+ , and Na 2 Y 2 B 2 O 7 :Bi show a blue emission under near-ultraviolet excitation. − Materials containing divalent bismuth such as M 2 P 2 O 7 (M = Ca, Sr, Ba) and MBPO 5 (M = Ca, Sr, Ba) exhibit red emission under ultraviolet/blue excitation. − Note that multiple Bi-active centers (Bi 2+ , Bi + , and Bi 0 ) can coexist in a single host like Ba 2 B 5 O 9 Cl and Sr 2 B 5 O 9 Cl, leading to the diverse luminescence peaks spanning from visible to NIR. − The luminescence properties of bismuth-doped materials are closely related to the valence state of bismuth ions . In this regard, concepts of controlling the valence state of bismuth in inorganic matrices are highly desired.…”