Photo and thermoluminescence of Eu doped ZnO nanophosphors

The photoluminescence (PL) and thermoluminescence (TL) studies of un-doped and Eu doped zinc oxide (ZnO) nanophosphors are presented in this paper. The paper also includes characterization by XRD and SEM for structural and morphological studies of chemically synthesized ZnO nanoparticles by using zinc acetate and ammonia solution. Thiourea was used for capping. The hexagonal structure of the undoped and Eu doped ZnO nanoparticles was observed. The XRD of rare earth doped sample showed an extra peak attributed to Europium oxide. The sizes of samples were ranging from 55 to 80 nm. SEM image of undoped ZnO nanoparticle showed flower like structure, whereas, no such shape was found for Eu doped ZnO nanoparticles. The excitation wavelength dependent PL and colour chromaticity diagram for both undoped and Eu doped ZnO was studied. Five samples of Eu doped ZnO, with 0.5%, 1%, 2.5%, 3% and 3.5% molar concentration of Eu were prepared. The variations in PL and TL with different concentrations of Eu were also studied. The Maximam PL and TL intensity was recorded for the samples containing 3% of Eu. The increase in the TL intensity for both the samples was found with increasing gamma dose (100-1500 Gy) without any saturation sign. The variations in TL intensity with changing heating rate (5-12 degrees C/s) were also studied. No change of TL glow peak position was seen for Eu doped sample. A linear increase of TL peak intensity with gamma dose suggests that, this phosphor could be used for dosimetry.

Automated summary

This paper presents the PL and TL studies of undoped and Eu-doped ZnO nanophosphors, characterized by XRD and SEM. Eu-doped samples showed an additional XRD peak attributed to Europium oxide, with sizes ranging from 55 to 80 nm. The TL intensity increased linearly with gamma dose, suggesting potential for dosimetry applications.