The role of heat treatment in improving photoluminescence and optically stimulated luminescence of HfO2

HfO2 is a metal oxide from the IV-B family whose properties have been widely applied in electronics and which displays an important blue emission. Despite this fact, few studies have been dedicated to understanding the role of heat treatment on its luminescence properties. Therefore, this study aimed to investigate the Photoluminescence (PL) and Optically Stimulated Luminescence (OSL) of HfO2 powder synthesized by the precipitation method and the influence of calcination on its luminescence. PL spectra results showed a broad emission band at about 2.6 eV, which was related to absorption at 4.1 eV. Green and blue stimulated luminescence spectra depicted emission bands in a similar region, varying between 2.44 up to 2.71 eV. The increase in the heat treatment temperature promoted signal enhancement, which could be associated with higher oxygen vacancy concentrations. OSL dose-response curves for the sample calcined at 1600 °C are linear up to 0.6 Gy and a good signal reproducibility is observed, which makes the material suitable for OSL dosimetry.