Low temperature synthesis of LiSi2N3 nanobelts via molten salt nitridation and their photoluminescence properties

LiSi2N3 nanobelts were synthesized using a novel low temperature molten salt nitridation technique using silicon and melamine as starting materials, and lithium chloride and sodium fluoride to form a reaction medium. The as-synthesized nanobelts were characterized by XRD, FESEM, HRTEM and SAED. The amount of LiSi2N3 increased with temperature. The optimal synthesis temperature for phase pure LiSi2N3 was about 1200 degrees C, which was about 200 degrees C lower than that required for the conventional solid-state reaction routes. LiSi2N3 nanobelts about a few hundred nanometers long and 50-200 nm in width were distributed uniformly in the final products. A possible growth mechanism was proposed based on the experimental results. Their photoluminescence emission at 459 nm (2.70 eV) at room temperature suggested that they could be potentially used in light-emitting nano-devices.