High efficient near-infrared (NIR) quantum cutting (QC) LuBO 3 :Ce 3+ ,Yb 3+ phosphors had been synthesized by hydrothermal method with further heat treatment. Due to the cooperative energy transfer (CET) from one Ce 3+ to two Yb 3+ ions, an intense NIR emission around 971nm of Yb 3+ : 2 F 5/2 → 2 F 7/2 transition was obtained under 369nm excitation. Yb 3+ concentration dependent quantum efficiency has been calculated and the maximum efficiency approaches up to 181% before reaching the critical concentration quenching threshold. Because the 971nm emission of Yb 3+ is matched with the band gap of crystalline Si, the phosphors may be applied potentially in silicon-based solar cells.