Controlled Chirality in Nanoscale Semi-Conducting CdTe Nanowires

Chirality is ubiquitous in nature – from the conformation of proteins within our cells to the photonic response seen in butterfly wings – and plays an important role in the functionality of a given molecule, building block, or particle assembly. Understanding how to harness and control the chirality of a nanoparticle assembly paves the way for devices such as chiral beam splitters and filters, as well as other photonic devices. Toward this end, the Kotov group has recently demonstrated the ability to dictate the handedness (left or right) of semi-conducting CdTe nanowire assemblies by capping the nanoparticle precursors with a chiral amino acid stabilizer, cysteine.¹ Using Monte Carlo and Molecular Dynamics computer simulations, we present a model for the assembly of these particles based upon the inter-particle forces present in the system. We first show that chirality can emerge spontaneously, but without predictability, in simple hard particle systems.  We next refine this model based on experimental parameters and show what mechanisms can be introduced to control this chirality and control the size and pitch of the nanowire.

[1] “Self-Assembly of Chiral Nanoparticles into Chiral Helices.” Yunlong Zhou, Ryan Marson, Greg Van Anders, Peter Ercius, Kai Sun, Bongjun Yeom, Sharon Glotzer, Nicholas A. Kotov. (preprint)