This study investigated the photoluminescent properties or Tb3+-Yb3+-, Ce3+-Tb3+-Yb3+-, and Eu2+-Yb3+-doped KSrPO4. The samples were prepared by a solid-state reaction with various doping concentrations. Emission at near-infrared range was focused on the application of luminescent solar concentrator for solar cells. Quantum cutting (QC) energy transfer was confirmed by the lifetimes of the donor. Near-infrared QC involved emission of Yb3+ ions was achieved by excitation of Ce3+ Tb3+, and Eu2+ ions, where the energy transfer processes occurred from Ce3+ to Tb3+ to Yb3+, Tb3+ to Yb3+, and Eu2+ to Yb3+, respectively. In addition, the concentration quenching effect of Yb3+ ions was avoided by low doping concentrations. The overall quantum efficiencies were calculated, and the maximum efficiency reaches 139%. The energy diagrams for divalent and trivalent rare-earth ions in KSrPO4 host lattice were analyzed. Results of this study demonstrate that heat-stable phosphate phosphors are promising candidates for increasing the efficiency of silicon-based solar cells.