Efficient blue to near-infrared luminescence properties in Pr3+- Yb3+ co-doped Li8Bi2(MoO4)7 phosphor

Down-conversion phosphors could absorb underutilized high-energy photons and convert to available near-infrared (NIR) photons in 900- 1100 nm improving the spectral mismatch of silicon-based solar cells. Herein, we report the preparation of Pr3+-Yb3+ co-doped Li8Bi2(MoO4)(7) molybdate phosphors by sol-gel method. The pure phases of all samples were confirmed by the X-ray diffraction. Under 453 nm blue light excitation, near infrared emission from Yb3+ and Pr(3+)can be generated. The NIR emission integral intensity of the Pr3+-Yb3+ co-doped sample was 1.6 times than that of the corresponding Pr3+ single-doped sample. The optimal doping concentration of Yb3+ was 0.05 and the highest efficiency was 62.7%, furthermore the energy transfer process in Pr3+-Yb3+ was analyzed. The results indicate that Li8Bi2(MoO4)(7): Pr3+, Yb3+ NIR phosphors have potential applications in the spectral converters of crystalline silicon solar cells.