학술논문

Ultrafast THz Conductivity Dynamics of a Novel Fe-Doped InGaAs Quantum Photoconductor
Document Type
Periodical
Source
IEEE Transactions on Terahertz Science and Technology IEEE Trans. THz Sci. Technol. Terahertz Science and Technology, IEEE Transactions on. 10(2):167-175 Mar, 2020
Subject
Fields, Waves and Electromagnetics
Antennas
Optical pulses
Optical pumping
Conductivity
Indium gallium arsenide
Doping
Optical variables measurement
Electron lifetimes
Fe doping
III–V semiconductors
indium compounds
photoconductor
terahertz (THz)
time-domain spectroscopy (TDS)
THz conductivity
wavelength 1550 nm
Language
ISSN
2156-342X
2156-3446
Abstract
We propose an Fe-doped, InGaAs-based semiconductor heterostructure optimized for the application as an ultrafast photoconductor and investigate its optical as well as THz properties. A sample series with varying doping concentration is grown by molecular-beam epitaxy. After examination of its static optical properties, the pump-induced intraband carrier dynamics are investigated via optical pump-THz probe measurements. Here, we observe conductivity decay times as low as 0.23 ps which are attributed to electron capture into Fe-related defects. These results are corroborated by monitoring the corresponding interband dynamics via all-optical pump-probe measurements. In addition, the competitiveness of THz detectors fabricated from a subset of these samples is demonstrated by integrating them into a standard time-domain spectrometer.