Reversible Strain-Induced Electron鈥揌ole Recombination in Silicon Nanowires Observed with Femtosecond Pump鈥揚robe Microscopy
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- 作者：Erik M. Grumstrup ; Michelle M. Gabriel ; Christopher W. Pinion ; James K. Parker ; James F. Cahoon ; John M. Papanikolas
- 刊名：Nano Letters
- 出版年：2014
- 出版时间：November 12, 2014
- 年：2014
- 卷：14
- 期：11
- 页码：6287-6292
- 全文大小：338K
- ISSN：1530-6992
文摘
Strain-induced changes to the electronic structure of nanoscale materials provide a promising avenue for expanding the optoelectronic functionality of semiconductor nanostructures in device applications. Here we use pump鈥損robe microscopy with femtosecond temporal resolution and submicron spatial resolution to characterize charge鈥揷arrier recombination and transport dynamics in silicon nanowires (NWs) locally strained by bending deformation. The electron鈥揾ole recombination rate increases with strain for values above a threshold of 鈭?% and, in highly strained (鈭?%) regions of the NW, increases 6-fold. The changes in recombination rate are independent of NW diameter and reversible upon reduction of the applied strain, indicating the effect originates from alterations to the NW bulk electronic structure rather than introduction of defects. The results highlight the strong relationship between strain, electronic structure, and charge鈥揷arrier dynamics in low-dimensional semiconductor systems, and we anticipate the results will assist the development of strain-enabled optoelectronic devices with indirect-bandgap materials such as silicon.