Carrier Dynamics in Si Nanowires Fabricated by Metal-Assisted Chemical Etching
详细信息 查看全文
- 作者：Hao Tang ; Li-Guo Zhu ; Liang Zhao ; Xuejin Zhang ; Jie Shan ; Shuit-Tong Lee
- 刊名：ACS Nano
- 出版年：2012
- 出版时间：September 25, 2012
- 年：2012
- 卷：6
- 期：9
- 页码：7814-7819
- 全文大小：406K
- 年卷期：v.6,no.9(September 25, 2012)
- ISSN：1936-086X
文摘
Silicon nanowire arrays fabricated by metal-assisted wet chemical etching have emerged as a promising architecture for solar energy harvesting applications. Here we investigate the dynamics and transport properties of photoexcited carriers in nanowires derived from an intrinsic silicon wafer using the terahertz (THz) time-domain spectroscopy. Both the dynamics and the pump fluence dependence of the photoinduced complex conductivity spectra up to several THz were measured. The photoinduced conductivity spectra follow a Lorentz dependence, arising from surface plasmon resonances in nanowires. The carrier lifetime was observed to approach 0.7 ns, which is limited primarily by surface trapping. The intrinsic carrier mobility was found to be 1000 cm2/(V路s). Compared to other silicon nanostructures, these relative high values observed for both the carrier lifetime and mobility are the consequences of high crystallinity and surface quality of the nanowires fabricated by the metal-assisted wet chemical etching method.