Self-Assembled Colloidal Superparticles from Nanorods

Beyond Quantum Dots Semiconducting colloidal nanoparticles—quantum dots—are of interest for their unusual properties. One current challenge is the controlled assembly of colloidal particles into larger structures, such as two-dimensional lattices on a substrate, or three-dimensional superparticles. Wang et al. (p. 358 ) present a two-step self-assembly of CdSe/CdS semiconductor nanorods to form mesoscopic colloidal superparticles. The particles show well-defined super-crystalline domains with dimensions ranging from hundreds of nanometers to several microns, and with the particle morphology controlled by the number of constituent rods. Films of the needle-shaped superparticles were able to act as polarizing light-emitting diodes.