Abstract
We investigate the relaxation dynamics of photogenerated carriers in silicon nanowires consisting of a crystalline core and a surrounding amorphous shell, using femtosecond time-resolved differential reflectivity and transmission spectroscopy at 3.15 eV and 1.57 eV photon energies. The complex behaviour of the differential transmission and reflectivity transients is the mixed contributions from the crystalline core and the amorphous silicon on the nanowire surface and the substrate where competing effects of state-filling and photoinduced absorption govern the carrier dynamics. Faster relaxation rates are observed on increasing the photogenerated carrier density. Independent experimental results on crystalline silicon-on-sapphire (SOS) help us in separating the contributions from the carrier dynamics in crystalline core and the amorphous regions in the nanowire samples. Further, single-beam z-scan nonlinear transmission experiments at 1.57 eV in both open- and close-aperture configurations yield two-photon absorption coefficient β (~3 cm/GW) and nonlinear refraction coefficient γ (–2.5 × 10 − 4 cm2/GW).
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References
D D D Ma, C S Lee, F C K Au, S Y Tong and S T Lee, Science 299, 1874 (2003)
Y Cui, Z Zhong, D Wang, W U Wang and C M Lieber, Nano Lett. 3, 149 (2003)
P Servati, A Colli, S Hofmann, Y Q Fu, P Beecher, Z A K Durrani, A C Ferrari, A J Flewitt, J Robertson and W I Milne, Physica E38, 64 (2007)
R Agarwal and C M Lieber, Appl. Phys. A85, 209 (2006)
S T Picraux, S A Dayeh, P Manandhar, D E Perea and S G Choi, J. Mater. 62, 35 (2010)
L F Cui, R Ruffo, C K Chan, H Peng and Y Chui, Nano Lett. 9, 491 (2008)
Y Dong, G Yu, M C McAlpine, W Lu and C M Lieber, Nano Lett. 8, 386 (2008)
M Taguchi, K Kawamoto, S Tsuge, T Baba, H Sakata, M Morizane, K Uchihashi, N Nakamura, S Kiyama and O Oota, Prog. Photov oltaics 8, 503 (2000)
M M Adachi, M P Anantram and K S Karim, Nano Lett. 10, 4093 (2010)
R P Prasankumar, S Choi, S A Trugman, S T Picraux and A J Taylor, Nano Lett. 8, 1619 (2008)
C-K Sun, S-Z Sun, K-H Lin, K Y-J Zhang, H-L Liu, S-C Liu and J-J Wu, Appl. Phys. Lett. 87, 023106 (2005)
A Othonosa, E Lioudakis, U Philipose and H E Ruda, Appl. Phys. Lett. 91, 241113 (2007)
C R Carey, Y Yu, M Kuno and G V Hartland, J. Phys. Chem. C113, 19077 (2009)
A Kar, P C Upadhya, S A Dayeh, S T Picraux, A J Taylor and R P Prasankumar, IEEE J. Sel. Top. Quant. Electron. 17, 889 (2011)
V R Almeida, C A Barrios, R R Panepucci and M Lipson, Nature 43, 1081 (2004)
J Qi, A M Belcher and J M White, Appl. Phys. Lett. 82, 2616 (2003)
K P H Lui and F A Hegmann, J. Appl. Phys. 93, 9012 (2003)
K P H Lui and F A Hegmann, Appl. Phys. Lett. 78, 3478 (2001)
K Narayana and S F Preble, Opt. Exp. 18, 8998 (2010)
J Kudrna, P Maly, F Trojanek, J Stepanek, T Lechner, I Pelant, J Meier and U Kroll, Mater. Sci. Eng. B69–70, 238 (2000)
K Ikeda, Y Shen and Y Fainman, Opt. Exp. 15, 17761 (2007)
R A Street, Appl. Phys. Lett. 41, 1060 (1982)
M M Adachi, M P Anantram and K S Karim, Nano Lett. 10, 4093 (2010)
S Kumar, M Anija, N Kamaraju, K S Vasu, K S Subrahmanyam, A K Sood and C N R Rao, Appl. Phys. Lett. 95, 191911 (2009)
S Kumar, N Kamaraju, K S Vasu, A Nag, A K Sood and C N R Rao, Chem. Phys. Lett. 499, 152 (2010)
M Dinu, F Quochi and H Garcia, Appl. Phys. Lett. 82, 2954 (2003)
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KUMAR, S., KHORASANINEJAD, M., ADACHI, M.M. et al. Probing ultrafast carrier dynamics, nonlinear absorption and refraction in core–shell silicon nanowires. Pramana - J Phys 79, 471–481 (2012). https://doi.org/10.1007/s12043-012-0337-y
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DOI: https://doi.org/10.1007/s12043-012-0337-y