Molten salt-assisted low-temperature synthesis of truncated hexagonal pyramidal InxGa1-xN nanocrystals with tunable optical properties.

Morphology-controlled chemical synthesis of ternary III-nitride nanocrystals is hindered by the inherent difficulty of simultaneously achieving alloy formation and anisotropic crystal growth. Here, we demonstrate that a KCl-MgCl2 eutectic molten salt (KCl/MgCl2 = 1.52 : 1 by weight) combined with lithium amide allows the formation of InxGa1-xN nanocrystals at a relatively low temperature of 500 °C. Highly crystalline InGaN nanocrystals with characteristic truncated hexagonal pyramidal features were obtained across the investigated composition range, as revealed by electron microscopy, while X-ray diffraction confirmed the formation of the wurtzite InGaN phase. Systematic In incorporation produces a composition-dependent red shift in the room-temperature photoluminescence from 577 to 661 nm, consistent with the observed variation in alloy composition. These findings highlight the potential of molten-salt-assisted nitridation as a low-temperature strategy for the synthesis of faceted ternary III-nitride nanocrystals and provide further insight into the crystal-growth behavior of multicomponent III-nitride semiconductors.