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

Abstract

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 °C, which was about 200 °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.