Infrared and visible scintillation of Ho3+-doped YAG and YLF crystals

Abstract

In our effort to develop a new kind of detector for low-energy, low-rate energy deposition events we have investigated the cathodo-and radioluminescence of Ho:YAG and Ho:YLF single crystals in an extended wavelength range from 200 nm to 2200 nm. The emission spectra of both crystals show a much more intense emission in the infrared range than in the visible one. We estimate an infrared light yield of 40 photons/keV when exciting the crystals with X-rays of energy ≈ 30 keV. The main reason of this high value is due to the Ho 3+ ions energy levels scheme that allows efficient cross relaxation processes to occur even at low dopant concentration.

Synthesis, characterization and photophysical properties of a new family of rare-earth cluster-based metal–organic frameworks

“…50 Ho-CU-45 also shows both visible and nearinfrared emissions (Figure S10b,c and S17b,c), with a broad and low-intensity 5 F 5 → 5 I 8 emission in the visible region at 660 nm, and 5 F 5 → 5 I 7 , 6 and 5 F 4 → 5 I 5 emission in the NIR region at 975, 1470, and 1320 nm, respectively. 51,52 Interestingly, Yb-CU-45 (Figure S10b,c and 21b,c), with an emitting state that is 13 400 cm -1 from the T 1 of the linker, also demonstrates the antenna effect, as an intense peak at 983 nm can be observed, assigned to the 2 F 5/2 → 2 F 7/2 transition. 53 Both Tm(III) and Er(III) are well known to undergo self-quenching due to cross relaxation between 4f states that are close in energy, resulting in non-radiative decay.…”

High infrared light yield of Erbium-doped fluoride crystals

“…Most scintillators have, however, a much lower efficiency as in (RE x Y 1−x ) 3 Al 5 O 12 crystals (RE x =Nd 1.1%, Tm 4.4%, Ho 2.5%), in which few photons/keV LYs in the visible range have been reported. As the investigated wavelength range was extended, a tenfold infrared (IR) emission intensity was observed as compared to the visible compo-nent [5,6]. Presumably, efficient energy transfer is one of the process responsible for such high LY, but it may not be the only one.…”