Laser hyperacoustic spectroscopy of single crystal germanium
Laser hyperacoustic spectroscopy of single crystal germanium
复制标题
单晶锗的激光超声光谱
DOI：
10.1134/1.1469160
复制
发表时间：
2002
影响因子：
1.1
通讯作者：
V. Gusev
中科院分区：
文献类型：
--
作者：
N. Chigarev;D. Y. Parashchuk;Yun Pan;V. Gusev
利用光热激光偏转技术研究了锗单晶中激光诱导超声波脉冲的时间分辨。结果表明，超声波脉冲的激发是由于光生载流子与晶格的电子变形相互作用，这是更有效的热弹性机制的声波产生。研究了与衍射和声吸收效应有关的超声波脉冲波形的演化。超声波信号的分析，使我们能够估计的光生载流子的双极扩散系数和超声波阻尼系数。研究了室温下激光激发锗中电子-空穴等离子体的波前以超声速传播。
Using a photothermal laser deflection technique the profiles of laser-induced hyperacoustic pulses in single crystal germanium were studied at a subnanosecond time resolution. It is shown that the hyperacoustic pulses are excited due to an electron-deformation interaction of photogenerated carriers with the crystal lattice, which is much more effective than the thermoelastic mechanism of the acoustic wave generation. Evolution of the hyperacoustic pulse profiles related to the diffraction and acoustic absorption effects was studied. An analysis of the hyperacoustic signal profiles allowed us to estimate the coefficient of ambipolar diffusion of the photogenerated charge carriers and the coefficient of hyperacoustic wave damping. It is established that the front of the electron-hole plasma laser-excited in germanium at room temperature propagates at a supersonic velocity.