Correlation of luminescence measurements to the structural characterization of Pr3+-doped HfSiOx

Abstract Luminescence and structural properties of Pr3+ doped HfSiOx thin layer elaborated by magnetron sputtering have been investigated as a function of the annealing temperature. The emission properties of Pr3+ ions were studied using photoluminescence (PL) and cathodoluminescence (CL) spectroscopies. Phase separation between amorphous SiO2 and crystallized HfO2 nano-grains occurring in the HfSiOx matrix has been investigated by atom probe tomography and transmission electron microscopy with particular consideration for the Pr distribution. Both PL and CL measurements evidenced a strong emission originating from Pr3+ ions in the visible range for an annealing temperature higher than 950°C. At 950°C, Pr3+ ions are clearly located in HfO2 nano-grains of cubic structure. Regarding PL, no significant changes are observed between 950°C and 1050°C. However, CL measurements revealed new emission peaks in the infrared range after an annealing at 1050°C, corresponding to the appearance of a new orthorhombic crystalline structure of HfO2 nano-grains in the thin layer. The CL signal evolution as a function of the annealing treatment is discussed in regard to the evolution of structural properties.