Sensitized Luminescence of CaF[sub 2]:(Ce + Mn)

Abstract

Calcium fluoride activated by cerium and manganese is shown to be a sensitized phosphor of high quantum efficiency. Studies of its reflection and excitation spectrum reveal that both cerium singlets and aggregates of cerium ions serve as sensitizers for manganese. The range of interaction (K) over which energy may be transferred from sensitizer to activator was found to be from 30 to 80 lattice sites. Variation in K with increasing sensitizer and constant manganese concentration is interpreted as being due to the competition of two types of sensitizing centers rather than to an energy transfer between sensitizer ions.

Recent advances in energy transfer in bulk and nanoscale luminescent materials: from spectroscopy to applications

“…62 For instance, in the well-known red phosphor YVO 4 :Eu 3+ , 63,64 excitation in the UV region from 300 nm to 400 nm is highly efficient for the generation of red emission by the transition of 5 D 0 -7 F 2 (see Fig. 62,[67][68][69][70] On the other hand, Yb 3+ often behaves as an efficient donor center to sensitise near infrared (NIR) emission because its f-f transition by 2 F 7/2 -2 F 5/2 has relatively large absorption cross section near 980 nm. 62,65,66 On the other hand, optical centers with 6s 2 electronic configuration such as Bi 3+ , Pb 2+ , and 5s 2 , Sn 2+ , and Ce 3+ , are naturally host-sensitized and are often used in scintillator materials due to their short fluorescence lifetime (o50 ns).…”

“…To this end, RE ions with allowed d-f transitions, such as Ce 3+ and Eu 2+ , have been frequently employed as sensitizers for other RE ions with thin f-f transition lines as well as TM ions, such as Mn 2+ (see Table S2, ESI, † for examples). 62,[67][68][69][70] On the other hand, Yb 3+ often behaves as an efficient donor center to sensitise near infrared (NIR) emission because its f-f transition by 2 F 7/2 -2 F 5/2 has relatively large absorption cross section near 980 nm. [71][72][73] (see Table S2, ESI, † for more examples).…”

Nanoscale “fluorescent stone”: Luminescent Calcium Fluoride Nanoparticles as Theranostic Platforms

“…Fluorite has been known for hundreds of years. Early researches were mainly on its applications in radiometers used to detect human exposure doses of high-energy radiation, such as X-rays, γ-rays, α-particles, or β-particles 33,35,38,44,45. The studies on fluorite's nano-counterparts only started in modern times.…”

Developments in Luminescence and Display Materials Over the Last 100 Years as Reflected in Electrochemical Society Publications

“…Bismuth, antimony, and samarium impurities were found to result in blue, greenish white, and reddish emissions, respectively. Ginther 36 gave results of luminescence of CaF 2 :(Ce ϩ Mn) where the Mn impurity acts as an activator and the Ce as a sensitizer. In 1955, Ranby and Henderson 37 reported on the preparation of magnesium fluorosilicate phosphors, doped with Ti and Mn, and concluded that the mechanism of luminescence includes sensitization by Ti.…”