X-ray excited luminescence property of ZnS:Cu, Tm fine particles synthesized by hydrothermal method

Abstract

The ZnS:Cu,Tm X-ray phosphor fine particles synthesized by hydrothermal method has been reported for first time and its photoluminescence (PL) and X-ray excited luminescence (XEL) properties have been studied in detail also. The direct hydrothermal treatment at 200 ℃ for 12h samples average gain size is about 15 nm; the synthesized spherical-like nanocrystals with well dispersity and narrow gain size distribution show cubic structure. The after annealing in Argon at 900 ℃ for 1h samples agglomerate size is about 200—600 nm and roughly spherical fine particles show pure hexagonal structure. The PL and XEL spectra of all of samples show a broad emission band and an intense emission band in the range of 400—600 nm. The maximum XEL intensity of sample directly synthesized by hydrothermal treatment is observed for Cu/Zn and Tm/Cu are 3×10-4 and 2, respectively. In this condition, the strongest PL and XEL emission is observed for the direct synthesized sample further annealing in Argon at 900℃ for 1h sample and the XEL peak center about 453 nm and 525 nm, respectively. The Samples with highly luminescence efficiencies and the smaller size could enhance the resolution of imaging systems. The difference between PL and XEL spectrum is due to its different excitation mechanism. The luminescence mechanism and different excitation mechanism of PL and XEL have been discussed.