Structure and cathodoluminescence properties of Dy³⁺ and Tb³⁺ doped AlN films

For the first time, Tb³⁺ and Dy³⁺ co-doped AlN films were prepared using ion implantation, and their crystal structure, cathodoluminescence properties and energy transfer mechanism were investigated. Raman scattering and X-ray diffraction results indicate that ion implantation of Dy³⁺ has caused increased compressive stress within the internal lattice when the dosage of Tb³⁺ remains constant. Continuous implantation led to the recombination of some point defects, resulting in a partial release of internal compressive stress. Cathodoluminescence spectra demonstrated that with high-dose Tb³⁺ implantation, the emission intensities of Tb³⁺ and Dy³⁺ exhibited different trends with increasing Dy³⁺ dosage. We propose the existence of a resonance energy transfer from Tb³⁺ ions ⁵D₄→⁷F₆ to Dy³⁺ ions ⁶H_15/2→⁴F_9/2 in AlN films. Finally, we observe that under different implantation dose of Dy³⁺ ions to Tb³⁺ ions, the emission color of the sample shifts between yellow-green and orange-yellow, with color temperatures ranging from 4042 to 5119K. Adjusting the dose ratio of Dy³⁺ to Tb³⁺ enables effective control of chromaticity coordinates and color temperatures.