High-purity red up-conversion emission of Ba5Zn4Y8O21:Er3+,Yb3+ phosphor excited by 1550 nm laser diode

• An efficient Ba5Zn4Y8O21:Er3+,Yb3+ up-conversion phosphor was synthesized.
• 1550 nm LD with great penetrability was used for luminescence research.
• Much stronger red emission with great color purity and stability was obtained.
• The intensity ratio of red and green emission can reach 62.28.

A novel Ba5Zn4Y8O21:Er3+,Yb3+ up-conversion phosphor was synthesized via solid-state reaction method. The up-conversion luminescence properties of the phosphor excited by 1550 nm laser diode were investigated. Results showed that the characteristic emission peaks of Er3+ were located at 530, 550, 675, and 810 nm, which correspond to the transitions of 2H11/2 → 4I15/2, 4S3/2 → 4I15/2, 4F9/2 → 4I15/2, and 4I9/2 → 4I15/2, respectively. The up-conversion mechanisms were systematically studied through concentration and laser power dependence of the up-converted emissions. An evident tuning effect of Yb3+ on the luminescence of the phosphor was observed. An efficient red emission with high purity was obtained through the Er3+ → Yb3+ → Er3+ energy transfer process, and the intensity ratio of the red and green emissions could reach 62.28. Therefore, Ba5Zn4Y8O21:Er3+,Yb3+ can be an excellent up-conversion red emitter.

Highly efficient and stable oxide up-conversion materials, especially the materials with high-purity red, green or blue up-conversion emission, can adequately meet the demand for many applications, such as phosphors, up-conversion lasers, and solar cells. In this study, a novel Ba5Zn4Y8O21:Er3+,Yb3+ up-conversion phosphor was synthesized by solid-state reaction method. The up-conversion luminescence properties of the phosphor under 1550 nm (so-called eye-safe wavelength) excitation were researched in detail for the first time. The phosphor exhibits extremely weak green emission and a much stronger red emission with great color purity and stability. The intensity ratio of red and green emission can reach 62.28. These results indicate that the Ba5Zn4Y8O21:Er3+,Yb3+ can be an excellent up-conversion red emitter. Moreover, the obtained results can be used as theoretical and experimental basis for the application of up-conversion luminescence caused by 1550 nm excitation.Figure optionsDownload as PowerPoint slide