Ultrafast carrier dynamics in silicon: A two-color transient reflection grating study on a (111)surface
Ultrafast carrier dynamics in silicon: A two-color transient reflection grating study on a (111)surface
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DOI：
10.1103/physrevlett.81.5664
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发表时间：
1998-12-21
影响因子：
8.6
通讯作者：
Dai, HL
中科院分区：
文献类型：
--
作者：
Sjodin, T;Petek, H;Dai, HL
利用反射结构中的瞬态光栅技术，在飞秒时间尺度上对硅表面附近产生的受激载流子的动力学进行了表征。对于导带边缘以上1.4 +/- 0.6 eV能量范围内的电子及其相应的空穴，在载流子密度低于10（20）cm（-3）时通过声子散射弛豫的寿命被确定为240 fs。当载流子密度大于5 × 10 ~（20）cm ~（-3）时，弛豫时间急剧增加，这为载流子-声子散射的电荷屏蔽提供了第一个直接证据。
The dynamics of excited carriers generated near a silicon surface were characterized on femtosecond time scales using the transient grating technique in the reflection configuration. For electrons in the energy range 1.4 +/- 0.6 eV above the conduction band edge and their corresponding holes, the lifetime for relaxation through phonon scattering at carrier densities below 10(20) cm(-3) was determined to be 240 fs. This relaxation time increased sharply for carrier densities higher than 5 X 10(20) cm(-3), providing the first direct evidence for charge screening of carrier-phonon scattering in Si.