Title :
Excitons in Biological and Non-Biological Nano-Structured Systems: Progress Towards Bio-inspired Photodetectors
Author_Institution :
Univ. at Albany-SUNY, Albany
Abstract :
An exciton, an elementary excitation formed from a bound electron-hole pair, is the lowest optically excited state in semiconductors, and plays a prominent role in condensed matter physics. In reduced dimensional materials, including biological structures, excitonic transitions should dominate due to carrier confinement. Here, I will first describe excitonic transitions in the photocurrent spectra of carbon nanotube diodes as a model system to describe optical absorption in ID semiconductors. The sharp narrow peaks are associated with excitonic transitions, and peak # 1 corresponds to the lowest optically allowed exciton state. The observation of sharp narrow absorption peaks at room temperature in a semiconductor is unprecedented, and is due to strong optical transitions of excitons as compared to band-to-band transitions normally seen for bulk materials.
Keywords :
carbon nanotubes; elemental semiconductors; excitons; nanobiotechnology; photodetectors; photoelectron spectra; 1D semiconductors; C; bio-inspired photodetectors; biological nanostructured systems; bound electron-hole pair; carbon nanotube diodes; elementary excitation; excitonic transitions; excitons; optical absorption; optical transitions; photocurrent spectra; Absorption; Biological materials; Biomedical optical imaging; Carrier confinement; Excitons; Nanobioscience; Optical materials; Photodetectors; Physics; Semiconductor materials;
Conference_Titel :
IEEE/LEOS Summer Topical Meetings, 2007 Digest of the
Conference_Location :
Portland, OR
Print_ISBN :
1-4244-0926-8
Electronic_ISBN :
1099-4742
DOI :
10.1109/LEOSST.2007.4288344