THz intersubband dynamics in p-Si/SiGe quantum well structures

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• 作者：Pidgeon ; C.R. ; Murzyn ; P. ; Wells ; J.-P.R. ; Bradley ; I.V. ; Ikonic ; Z. ; Kelsall ; R.W. ; Harrison ; P. ; et. al.
• 关键词：78.47.+p ; 71.20.&minus ; b ; Si/SiGe ; Intersubband absorption ; Alloy scattering
• 刊名：Physica E
• 出版年：2002
• 出版时间：March, 2002
• 年：2002
• 卷：13
• 期：2-4
• 页码：904-907
• 全文大小：120 K

文摘

We report time-resolved (ps) studies of the dynamics of intersubband transitions in p-Si/SiGe multi-quantum well structures in the FIR regime, plankvω<plankvω_LO, utilizing the Dutch free electron laser, FELIX. The calculated scattering rates have been included in a rate equation model of the transient FIR intersubband absorption, and show excellent agreement with our degenerate pump–probe spectroscopy measurements where after an initial rise time determined by the resolution of our measurement we determine a decay time of 10ps. This is found to be approximately constant in the temperature range from 4 to 100K, in good agreement with the predictions of alloy scattering in the Si_0.7Ge_0.3 wells.