1. Tunable Electron-Phonon Coupling in Carbon Nanotubes Moonsub Shim, University of Illinois, DMR-0348585 EFEF K. Nguyen, A. Gaur, & M. Shim, Phys. Rev. Lett. 98, 145504 (2007). Shifting the Fermi level of a metallic carbon nanotube with an external potential leads to large changes in the Raman spectrum arising from varying coupling strengths between conduction electrons and lattice vibrations. Single-walled carbon nanotubes (SWNTs) are often considered as prototypical one-dimensional materials with outstanding electrical and mechanical properties. Yet many unresolved debates remain on our understanding of fundamental phenomena such as how electrons interact with atomic vibrations (phonons). Much of the difficulties arises from the all-surface-atom makeup of SWNTs causing properties to be extremely sensitive to minute changes in the surrounding environment. Hence experimental observations are often difficult to interpret. We have exploited our unconventional approach of utilizing polymer electrolytes to screen out many varying factors and to provide a simple means of controlling the local chemical environment. We have combined this approach with Raman studies on individual SWNTs. The results provide not only new insights on electron-phonon coupling and how it depends on the number electrons in SWNTs but also important implications on how Raman spectroscopy may be used especially in characterizing chemical reactions for processing SWNTs.

2. Promoting Science Education and Undergraduate Research Moonsub Shim, University of Illinois, DMR-0348585 On-line Course: As a part of his CAREER award, the PI is developing an introductory materials science and engineering course into a class that can be offered on-line. A snapshot from a video taping session is shown on the right (top photo). This on-line course will be used to enrich curriculum in academic institutions such as nearby community colleges. It will also provide additional resources for undergraduate students in the PI’s department with below-average academic performances to catch up with their peers as well as for high school teachers to motivate young students to consider science and engineering majors. Curriculum development: The PI has developed and delivered several lectures on nanoscale materials which is currently being expanded into a new course on nanotechnology at the undergraduate level. The PI demonstrating quantum confinement in semiconductor nanocrystals is shown on the bottom left photograph. The PI has also integrated some of these lectures on nanoscale materials into the introductory materials science course. Undergraduate Research Opportunities: This project has and continues to provide many research opportunities for undergraduate researchers (bottom right photo). Based on former undergraduate students’ feedback, these research experiences have been one of the key motivating factors in their pursuits of graduate degrees. PI’s graduate students involved have also had valuable mentoring experiences.