Impact ionization in InSb probed by terahertz pump—terahertz probe spectroscopy

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[superscript 2], we observed carrier heat...

Full description

Bibliographic Details
Main Authors: Hoffmann, Matthias C., Hebling, Janos, Hwang, Harold Young, Yeh, Ka-Lo, Nelson, Keith Adam
Other Authors: Massachusetts Institute of Technology. Department of Chemistry
Format: Article
Language:en_US
Published: American Physical Society 2010
Online Access:http://hdl.handle.net/1721.1/51883
https://orcid.org/0000-0001-7804-5418
Description
Summary: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[superscript 2], we observed carrier heating and impact ionization dynamics. The number of carriers produced exceeds 10[superscript 16] cm[superscript −3], corresponding to a change in carrier density ΔN/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.