Radio-, thermo- and photoluminescence properties of Lu 2 O 3 :Eu and Lu 2 O 3 :Tb nanopowder and film scintillators

Abstract

This work is dedicated to the preparation and characterization of the radio-, thermo-, and photoluminescent properties of Lu 2 O 3 :Eu and Lu 2 O 3 :Tb nanopowder (NPs) scintillators, prepared by means of hydrothermal processing, and their film analogues made of these NPs by the spin coating method. The luminescent properties of NPs and films were characterized by cathodoluminescence (CL), photoluminescence (PL), X-ray excited radioluminescence (RL), and thermoluminescence (TL) at low and high temperatures. In Lu 2 O 3 :Eu NPs and films, mostly the luminescence of Eu 3+ ions occupying the C 2 site of the host, with the most intensive peaks at 611.6 nm and a decay time of 1.5 ms, was observed. On the contrary, two types of Tb 3+ centers in the C 2 and C 3i sites with the main emission lines at 542.4 and 544.0 nm and the corresponding 4f→5d excitation bands at 270 and 305 nm and decay times of t 1/e = 2.17 and 3.96 ms were observed in the case of Lu 2 O 3 :Tb NPs and films. Indications were noted that Tb 3+ in the C 3i symmetry position was most active in the CL spectra of Lu 2 O 3 :Tb NPs and a respective film. Thermoluminescent peaks at 110°C and 170°C for Lu 2 O 3 :Eu NPs and at 75°C and 120°C in Lu 2 O 3 :Tb NPs were observed corresponding to the hole and electron traps, respectively. Significantly different onsets of temperature quenching of Eu 3+ and Tb 3+ luminescence in Lu 2 O 3 :Eu and Lu 2 O 3 :Tb NPs were found at ~90°C and ~320°C, respectively.