Shape-controlled synthesis of semiconducting CuFeS₂ nanocrystals

Nanocrystals of the semiconducting chalcopyrite CuFeS₂ have been synthesized utilizing a facile solution-based method. Depending on the choice of precursors and synthesis conditions, the nanocrystals exhibit either a spherical (∼12 nm) or pyramidal morphology (∼30 nm), with a narrow size distribution. The band gap of the pyramidal nanocrystals is very close to the bulk value, but a larger band gap is obtained for the spherical nanocrystals likely because of size confinement effect.