Luminescent properties of Er3+-Eu3+ co-doped tellurite glass for white light LEDs

Tellurite glass samples doped with Er³⁺ and Eu³⁺ were synthesized by the high-temperature solid phase method. The XRD diffraction pattern shows the amorphous properties of the prepared samples. The luminescence properties of glass samples were analyzed using the absorption spectrum, excitation spectrum, and emission spectrum. The energy transfer mechanism between Er³⁺ ions and Eu³⁺ ions was studied by changing the concentration of Eu³⁺ ions, and the results were verified by measuring the luminescence decay lifetime. It is worth noting that at 380 nm excitation, Er³⁺ and Eu³⁺ co-doped tellurite glass exhibits remarkable tunable luminescence characteristics: by adjusting the concentration of Eu³⁺ ions, the emission color can be flexibly adjusted from green to orangish-red. In addition, by effectively combining the prepared co-doped glass sample with the 380 nm GaN chip, the cold white light emission with CIE coordinates of (0.324, 0.320) was successfully achieved. According to the variable-temperature spectroscopy, at 210℃, the emission peak intensities of the co-doped Er³⁺/Eu³⁺ tellurite glass at 547 nm and 613 nm are above 70% of the room-temperature luminescence intensity, demonstrating excellent thermal stability.

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