Transient transmission of THz metamaterial antennas by impact ionization in a silicon substrate.
Transient transmission of THz metamaterial antennas by impact ionization in a silicon substrate.
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DOI：
10.1364/oe.405555
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发表时间：
2020-12
期刊：
影响因子：
3.8
通讯作者：
M. Bejide;Yejun Li;N. Stavrias;B. Redlich;Takuo Tanaka;V. Lam;N. T. Tung;E. Janssens
中科院分区：
文献类型：
--
作者：
M. Bejide;Yejun Li;N. Stavrias;B. Redlich;Takuo Tanaka;V. Lam;N. T. Tung;E. Janssens
研究了不同波长下太赫兹超材料天线硅基板中受激电荷载流子的皮秒动力学。时间分辨太赫兹泵浦-太赫兹探针光谱是使用来自可调谐自由电子激光器的光在 9.3-16.7 太赫兹频率范围内使用 2-12 J/m2 的注量进行的。根据相对于共振中心的激发波长，观察到瞬态传输增加、减少或两者的组合。瞬态传输变化可以通过局部电场增强来解释，局部电场增强会引起硅基板中的碰撞电离，使局部载流子数量增加几个数量级，以及随后的扩散和复合。研究的超材料可以与常见的半导体器件集成，并有可能用于传感应用和太赫兹能量收集。
The picosecond dynamics of excited charge carriers in the silicon substrate of THz metamaterial antennas was studied at different wavelengths. Time-resolved THz pump-THz probe spectroscopy was performed with light from a tunable free electron laser in the 9.3-16.7 THz frequency range using fluences of 2-12 J/m2. Depending on the excitation wavelength with respect to the resonance center, transient transmission increase, decrease, or a combination of both was observed. The transient transmission changes can be explained by local electric field enhancement, which induces impact ionization in the silicon substrate, increasing the local number of charge carriers by several orders of magnitude, and their subsequent diffusion and recombination. The studied metamaterials can be integrated with common semiconductor devices and can potentially be used in sensing applications and THz energy harvesting.