Wydział Chemii

Ioannis Seferis

Justyna Zeler

C. Michail

I. Valais

G. Fountos

N. Kalyvas

A. Bakas

I. Kandarakis

Eugeniusz Zych

2016

Applied Physics A-Materials Science and Processing

122

526/1-526/10

10.1007/s00339-016-0081-0

Naukowa

Angielski

Artykuł

In the present work, we demonstrate the fabrication technique of highly translucent layers of nanoparticulated (~50nm) LuPO₄:Eu phosphor, present their basic luminescent properties and give results of their performance in a planar imaging system coupled to a CMOS photodetector. For comparison, the imaging performance of an opaque Gd₂O₂S:Eu phosphor screen prepared by sedimentation is also shown. The X-ray detection parameters as well as the luminescence efficiency of the investigated films were discussed. Results show that the in-line transmittance at ~600-700nm, in the range of the phosphor luminescence, varies with respect to the thickness of the films from 40 to 50% for a film of 67μm thick to 4-12% when the thickness increases to 460μm. Yet, X-ray detection parameters get enhanced as the thickness of the films increases. Those results affect the luminescence efficiency curves of the films under poly-energetic X-ray radiation of various tube energies. The normalized noise power spectrum values were found similar for LuPO₄:Eu films and a phosphor screen made using commercial Gd₂O₂S:Eu powder. The detective quantum efficiency of our films is clearly lower compared to the Gd₂O₂S:Eu screen from 2 to 10cyclesmm⁻¹ frequency range while the modulation transfer function is lower from 0 to 5.5cyclesmm⁻¹ frequency range. The acquired data allow to predict that high-temperature sintering of our films under pressure may help to improve their imaging quality, since such a processing should increase the luminescence efficiency without significant growth of the grains and thus without sacrificing their translucent character.

CC-BY

http://dx.doi.org/10.1007/s00339-016-0081-0

http://link.springer.com