【Substrate Papers】Pr³⁺-implanted β-Ga₂O₃ single crystals: A Comprehensive Theoretical and Experimental Investigation

      Researchers from the Universidade de Aveiro have published a dissertation titled "Pr³⁺-implanted β-Ga₂O₃ single crystals: A Comprehensive Theoretical and Experimental Investigation" in Optical Materials.

Abstract

      Monoclinic gallium oxide (β-Ga₂O₃) single crystals were successfully implanted with praseodymium (Pr) ions at either room temperature (RT) or 600 °C. Density functional theory (DFT) calculations were employed to investigate the impact of Pr doping on the electronic properties of β-Ga₂O₃. Structural characterization indicates that only the monoclinic crystalline phase is present after implantation and annealing treatments. The optical activation of the Pr³⁺ in the host matrix was achieved, exhibiting well-defined intraionic Pr³⁺ transitions. The distinct Pr³⁺ lines in the β-Ga₂O₃:Pr samples were associated with the presence of the Pr³⁺ optical centers in different lattice sites/local environments. In both samples, the blue and red Pr³⁺ luminescence was observed to be preferentially populated via inter-configurational 4f²→4f5d absorption with the 4f5d levels placed within the β-Ga₂O₃ conduction band. Intersystem crossing between the ³P_J and ¹D₂ manifolds with the 4f5d levels is a relaxation process that accounts for the Pr³⁺ luminescence. The RT lifetime of red Pr³⁺ emission is fitted to a bi-exponential decay for both samples. Temperature-dependent photoluminescence (PL) measurements reveal a thermal population of red luminescence for the Pr³⁺ centers, described by an activation energy of ca. 40 meV, and the samples' emission color is tuned from UV/blue to red.

DOI：

https://doi.org/10.1016/j.optmat.2025.117692