Heterogeneously Alloyed Semiconductor Nanocrystals with Induced Chemical Composition Gradients

Abstract

Semiconductor nanocrystals of CdSSe exhibiting chemical composition gradients are synthesized via a facile, one-pot synthesis. Varying degrees of gradation are observed as growth temperatures are manipulated to alter rates of reactivity for anionic precursors. Stoichiometries, with growth time and change in temperature, are determined using Rutherford backscattering spectroscopy (RBS) to demonstrate chemical composition gradients. Sizes and structures of compositionally graded CdSSe nanocrystals are determined using transmission electron microscopy and X-ray diffraction techniques, respectively. We employ absorption spectroscopy and photoluminescence techniques to elucidate corresponding optical properties. Nanocrystals with chemical composition gradients demonstrating enhanced luminescence efficiency could be the key to improved nanocrystal optical performance.