Ultrafast Relaxation Dynamics via Acoustic Phonons in Carbon Nanotubes
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- 作者：Olga A. Dyatlova ; Christopher K枚hler ; Ermin Malic ; Jordi Gomis-Bresco ; Janina Maultzsch ; Andrey Tsagan-Mandzhiev ; Tobias Watermann ; Andreas Knorr ; Ulrike Woggon
- 刊名：Nano Letters
- 出版年：2012
- 出版时间：May 9, 2012
- 年：2012
- 卷：12
- 期：5
- 页码：2249-2253
- 全文大小：285K
- 年卷期：v.12,no.5(May 9, 2012)
- ISSN：1530-6992
文摘
Carbon nanotubes as one-dimensional nanostructures are ideal model systems to study relaxation channels of excited charged carriers. The understanding of the ultrafast scattering processes is the key for exploiting the huge application potential that nanotubes offer, e.g., for light-emitting and detecting nanoscale electronic devices. In a joint study of two-color pump鈥損robe experiments and microscopic calculations based on the density matrix formalism, we extract, both experimentally and theoretically, a picosecond carrier relaxation dynamics, and ascribe it to the intraband scattering of excited carriers with acoustic phonons. The calculated picosecond relaxation times show a decrease for smaller tube diameters. The best agreement between experiment and theory is obtained for the (8,7) nanotubes with the largest investigated diameter and chiral angle for which the applied zone-folded tight-binding wave functions are a good approximation.