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arXiv · 2208.07392

Impact ionization in low-band-gap semiconductors driven by ultrafast THz excitation: beyond the ballistic regime

Simone Biasco·Florence Burri·Sarah Houver·Elsa Abreu·Matteo Savoini·Steven L. Johnson
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Abstract

Using two-dimensional THz spectroscopy in combination with numerical models, we investigate the dynamics linked to carrier multiplication caused by high-field THz excitation of the low-gap semiconductor InSb. In addition to previously observed dynamics connected with quasi-ballistic carrier dynamics, we observe other spectral and temporal features that we attribute to impact ionization for peak fields above 60 kV/cm, which continue up to the maximum investigated peak field of 430 kV/cm. At the highest fields we estimate a carrier multiplication factor greater than 10 due to impact ionization, which is well-reproduced by a numerical simulation of the impact ionization process which we have developed.

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Simone Biasco, Florence Burri, Sarah Houver, Elsa Abreu, Matteo Savoini, Steven L. Johnson. 2022-08-15. Impact ionization in low-band-gap semiconductors driven by ultrafast THz excitation: beyond the ballistic regime. https://doi.org/10.1103/physrevb.106.235201

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