Impact ionization in InSb probed by terahertz pump-terahertz probe spectroscopy
Impact ionization in InSb probed by terahertz pump-terahertz probe spectroscopy
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DOI：
10.1103/physrevb.79.161201
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发表时间：
2009-04-01
影响因子：
3.7
通讯作者：
Nelson, Keith A.
中科院分区：
文献类型：
--
作者：
Hoffmann, Matthias C.;Hebling, Janos;Nelson, Keith A.
在200和80 K下研究了宽带远红外辐射激发下锑化铟（InSb）中皮秒载流子的动力学。使用太赫兹泵浦/太赫兹探测方案，泵浦太赫兹场为100 kV/cm，强度为100 MW/cm（2），我们观察到载流子加热和碰撞电离动力学。产生的载流子数超过10（16）cm（-3），对应于80 K时载流子密度变化Δ N/N为700%。在1.2 THz处的明确定义的吸收峰的开始是由于热电子的冷却而导致的纵向光学（LO）和纵向声学（LA）声子群的变化的指示。
Picosecond carrier dynamics in indium antimonide (InSb) following excitation by below band gap broadband far-infrared radiation was investigated at 200 and 80 K. Using a THz-pump/THz-probe scheme with pump THz fields of 100 kV/cm and an intensity of 100 MW/cm(2), we observed carrier heating and impact ionization dynamics. The number of carriers produced exceeds 10(16) cm(-3), corresponding to a change in carrier density Delta N/N of 700% at 80 K. The onset of a well-defined absorption peak at 1.2 THz is an indication of changes in longitudinal optical (LO) and longitudinal acoustic (LA) phonon populations due to cooling of the hot electrons.