The challenge of developing phosphors with tailored near-infrared (NIR) emission ranges to meet the diverse demands of various applications is a paramount concern in the contemporary realm of NIR phosphor research. A strong dependence of NIR emission on Cr 3+ concentration has been demonstrated in Sc 2- x Si 2 O 7 : x Cr 3+ , which exhibits an NIR emission band at 840 nm for low Cr 3+ doping concentrations ( x = 0.001-0.01) and an anomalous NIR emission band at 1300 nm for high Cr 3+ doping concentrations ( x = 0.01-0.10). Careful investigation of the crystal structure, excitation and emission spectra, and luminescence decay curves indicates that the two NIR emissions can be attributed to the isolated Cr 3+ ions and the Cr 3+ -Cr 3+ pairs, respectively. The strong interaction of exchange-coupled Cr 3+ -Cr 3+ pairs is supported by temperature-dependent emission spectra, luminescence decay curves and electron paramagnetic resonance (EPR) measurements. This work provides a new insight into the study of Cr 3+ -Cr 3+ pairs for broadband NIR emission.