Herman Group Research 

Current research in the Herman group is directed to the assembly of nanostructured materials and devices, and the optical and mechanical properties of nanocrystals and nanomaterials.

This effort focuses on the properties of nanocrystals and how they and other nano-based structures can be used to form complex films other assemblies. The emphasis of this work is on (1) directed and self assembly of patterned and unpatterned films and device structures of nanocrystals by using electrophoretic deposition and of carbon nanotubes and of nanowires by dielectrophoretic deposition and (2) the analysis of the optical, mechanical, and electrical properties of these nanocrystals and films. This has included the use of optical spectroscopy, for example using Raman scattering to examine mechanical properties, phase transitions and the effects of phonon confinement, and infrared spectroscopy to probe surface ligands. Much of this recent work was done with the NSF Materials Research Science and Engineering Center (MRSEC) at Columbia. Some of the work is also funded by the NSF Nanocenter (NSEC) and the Energy Frontiers Research Center (EFRC) at Columbia and by DOE.

Earlier work in the Herman group focused on optical diagnostic probes of film processing, including during plasma chemical processing and laser processing, the optical physics of semiconductors and semiconductor heterostructures at elevated pressure in diamond anvil cells (and other studies of the effects of strain) and at elevated temperature to learn about the electronic and lattice properties of these structures atambient conditions and other nano-, meso-, and macro-porous materials, direct laser writing and other types of laser processing, laser isotope separation of deuterium and tritium, and laser-initiated chemical reactions.

Also, see Publications.