Pr³⁺ and Yb³⁺ co-doped phosphate glasses are prepared to study their optical properties. Excitation and emission spectra and decay curves are used to characterize their luminescence. We demonstrate that upon excitation of Pr³⁺ ion with one high energy photon at 470 nm, two near-infrared (NIR) photons are emitted at 950-1100 nm (Yb³⁺:²F^5/2 ->²F_7/2) through an efficient cooperative energy transfer (CET) from Pr³⁺ to Yb³⁺. The maximum energy transfer efficiency (ETE) and the corresponding quantum efficiency approach up to 90.17% and 190.17%, respectively. The glass materials might find potential application for improving the efficiency of silicon-based solar cells.