Tuned light emission from nanoparticles of cadmium chalcogenides and nanostructures in indium nitride

The synthesis of polymer nanoparticle composites consisting of CdSe or CdS with a polymer containing pendant phosphine group, prepared by modification of polybutadiene, is reviewed. The CdSe composites give near band edge emission for larger particles, but white light emission, apparently from energy transfer into an emitting state of the polymer for smaller particles. Blue emission is obtained from CdS within the same polymer, provided it is kept under an inert atmosphere. The synthesis of InN nanoparticles from the co-decomposition of [InCl2N3](2) with Li[NSiMe3] in diisopropylbenzene is also described. The as-prepared particles are mixed with In metal, which is in turn removed by washing with dilute HCl followed by I-2/THF to give hexagonal or cubic InN particles with average diameters of 20-30 nm. Addition of iodine gives smaller (7 nm) more uniform particles mainly of hexagonal InN. Using Li3N as an additional source leads to In/InN core shell fibers by a solution- liquid-solid growth mechanism, from which the indium cores can be removed by washing with dilute HCl followed by I-2/THF to give thick walled InN nanotubes ca. 15 nm in diameter with a wall thickness of 5 nm.