| AVS 61st International Symposium & Exhibition | |
| Thin Film | Wednesday Sessions |
| Session TF+EM+EN-WeA |
| Session: | Thin Film and Nanostructured Coatings for Light Trapping, Extraction, and Plasmonic Applications |
| Presenter: | George Larsen, University of Georgia, Athens |
| Authors: | G.K. Larsen, University of Georgia, Athens Y. He, University of Georgia, Athens W. Ingram, University of Georgia, Athens Y.P. Zhao, University of Georgia, Athens |
| Correspondent: | Click to Email |
An object is said to be “chiral” if it cannot be made superimposable upon its mirror image solely by rotations and translations. That is, chiral objects do not exhibit reflective symmetry. By combining self-assembled colloid monolayers and glancing angle deposition (GLAD), we can create chiral patchy particle thin films that exhibit plasmonic activity in the visible region. Due to their chirality, these patchy particle films exhibit circular dichroism, i.e., they absorb right- and left-circular polarized light to different degrees. Interestingly, we find that the GLAD method relaxes requirements on the template quality, allowing for the production strongly chiral films from polycrystalline colloidal monolayers with randomly oriented domains. It is determined that the rotation direction during GLAD breaks the racemic symmetry of the templates by creating a chiral distribution of material which enhances the chirality of one set of enantiomers relative to the other. Microscopic analysis and geometric chirality calculations confirm that the optical chirality of the bulk film results from incomplete cancellations of even stronger local chiralities. By improving the quality of the colloidal monolayers and intentionally creating a chiral material distribution, we seek to use these chiral patchy particle arrays as plasmonic biosensors that are sensitive to the handedness of the target molecule.