Professor
Department of Applied Physics & Applied Math
iph1@columbia.edu
Herman Group Webpage

My research concentrates on the fundamental aspects and applications of laser interactions with matter and nanoscience. This includes properties of nanocrystals and films composed of nanocrystals, assembling nanocomponents using electric fields, optical physics of the solid state, molecular and chemical physics, thin film processing, and optical spectroscopy. One active area of research in my group is the study of the optical and mechanical properties of semiconductor and metal oxide nanocrystals and films composed of them. This includes Raman analysis of these nanocrystals and understanding how films of these particles can be made, including by using electric fields for directed assembly. In addition to such electrophonetic deposition, I use dielectrophoetic methods to precisely place and align carbon nanotubes in electrode device structures.

I am also interested in optical spectroscopy of semiconductors, and in particular in the effects of strain, confinement and temperature on these materials. I have studied the optical spectroscopy of materials subjected to high pressure in diamond anvil cells, including thin films, multiple-quantum wells, and nanocrystals of novel light-emitting IV, III-V, and II-VI semiconductors by using photoluminescence and other optical methods. I have also investigated strain and mechanical properties in nanocrystal films by using Raman scattering.

My research has also been in related areas of optical physics, including studies of optically pumped lasers, laser isotope separation, infrared laser multiple-photon dissociation, laser chemical modifications of surfaces, and optical microanalysis of semiconductors, and optical diagnostics of plasma etching and other types of thin film processing.

I have developed a first year/second year undergraduate course on “Physics of the Human Body” and am publishing a textbook of the same name (Springer, Berlin Heidelberg New York, 2007), and I have published the monograph “Optical Diagnostics for Thin Film Processing” (Academic Press, San Diego, 1996).

• S. Banerjee, B. White, L. Huang, B. J. Rego, S. O’Brien, and I. P. Herman, “Precise Positioning of Single-Walled Carbon Nantoubes by AC Dielectrophoresis,” J. Vac. Sci. Technol B (2006).
• S. Banerjee, S. Jia, D.I. Kim, R.D. Robinson, J. Kysar, J. Bevk, and I.P. Herman, “Raman Microprobe Analysis of Elastic Strain and Fracture in Electrophoretically-Deposited CdSe Nanocrystal Films,” Nano Letters 6, 175-180 (2006).
• R.D. Robinson, J. Tang, M.L. Steigerwald, L.E. Brus, and I.P. Herman, “Raman Scattering in HfxZr1-xO2 Nanoparticles,” Phys. Rev. B 71, 115408 (2005).
• M. Islam and I. P. Herman, “Electric-Field Assisted Deposition of Patterned Nanocrystal Films using Thermally Charged CdSe Nanocrystals”, Appl. Phys. Lett. 80, 3823-3825 (2002).
  F. Zhang, S.-W. Chan, J. E. Spanier, E. Apak, Q. Jin, R. D. Robinson, and I. P. Herman, “Cerium Oxide Nanoparticles: Size-selective Formation and Structure Analysis”, Appl. Phys. Lett. 80, 127-129 (2002).