Energy-Transfer Processes in Nonstoichiometric and Stoichiometric Er3+ , Ho3+ , Nd3+ , Pr3+ , and Cr3+ -Codoped Ce :YAG Transparent Ceramics: Toward High-Power and Warm-White Laser Diodes and LEDs

• DOI: 10.1103/physrevapplied.20.014047
• Publication Date: 2023-07-21T14:30:57Z
• Authors: Karol Bartosiewicz; Agnieszka Szysiak; Robert Tomala; Przemysław Gołębi...; Helena Węglarz; Vitali Nagirnyi; Marco Kirm; Ivo Romet; Maksym Buryi; Vitezslav Jary; Romana Kucerkova; Marek Wzorek; Ryszard Buczyński
• Keywords: Stoichiometry

Transparent light-converting ${\mathrm{Y}}_{3}{\mathrm{Al}}_{5}{\mathrm{O}}_{12}:\mathrm{Ce}$ (YAG:$\mathrm{Ce}$) ceramics have become promising materials for advanced light-emitting diode and laser-driven white-light-generation technology. However, their functionality is highly dependent on factors such as structural quality, uniformity of dopant distribution, the presence defects, cost fabrication. The emission YAG:$\mathrm{Ce}$ remains thermally stable when high-power-density laser excitation uniformly spread over entire surface area due to light-scattering processes. creation centers that can provide homogeneous white light in crucial. One drawbacks a material converting ultraviolet into lack red component, which results cold low color rendering index. Therefore, codoping YAG:${\mathrm{Ce}}^{3+}$ with red-emitting ions (${\mathrm{Er}}^{3+}$, ${\mathrm{Ho}}^{3+}$, ${\mathrm{Nd}}^{3+}$, ${\mathrm{Pr}}^{3+}$, ${\mathrm{Cr}}^{3+}$) was carried out slight nonstoichiometry induced present study improve photoconversion parameters. phase purity studied analyzed using powder x-ray diffraction SEM combined energy-dispersive spectroscopy (EDS). EDS studies revealed nonstoichiometric contained ${\mathrm{Al}}_{2}{\mathrm{O}}_{3}$ inclusions acted centers. Optical transmittance absorption spectra measurements imposed by nanodefects related perturbations local lattice structure dopants. mapping photoluminescence analysis showed formation $\mathrm{Ce}$-$\mathrm{Ln}$,$\mathrm{Cr}$ ($\mathrm{Cr}$ transition metal) pairs availability energy transfer between pair-forming ions. Intrinsic thermal quenching ${\mathrm{Ce}}^{3+}$ luminescence started above 400 K. YAG:$\mathrm{Ce},\mathrm{Nd}$ sample stability up 650 K luminous efficacy 198 lm/W. parameters transparent ceramic packaged blue or were compared. It shown temperature emissions could be controlled spectral width beam. Thermally stimulated applied investigate deep trapping codopants. A detailed EPR ${\mathrm{F}}^{+}$, ${\mathrm{O}}^{\ensuremath{-}}$, ${\mathrm{Ce}}^{4+}$