Synthesis and characterization of colloidal indium nitride nanocrystals and study of their electronic structure and size and shape dependent optical properties

In this work the synthesize colloidal Indium Nitride (InN) nanoparticles and characterization techniques to explain their morphology and different properties have been presented. The efficiency of previously reported synthetic methods have been tested and modifications have been attempted to enhance the quality of the nanocrystals. A novel approach has been successfully developed to synthesize 4-12 nm diameter, wurtzite phase InN nanoparticles with high crystallinity and quantitative photoluminescence quantum yield. This new synthetic method is based on the in-situ chemical reduction of indium(III) bidentate amine complexes in high-boiling point solvents. We demonstrate that the electronic structure of these material is strongly dependant on the size and shape of the nanoparticles. Due to quantum confinement playing a significant role the optical band gap of InN can be tuned to be up to 0.4 eV higher than the bulk material. The size of the nanoparticles can be controlled by the varying the precursor ratio, rate of addition of reactant whereas the shape can be modified by adjusting the nature and stoichiometry of the surfactants used during the synthesis.