Open AccessConfined photocarrier transport in InAs pyramidal quantum dots via terahertz time-domain spectroscopy
Author(s) -
Jorge Michael M. Presto,
Elizabeth Ann Prieto,
Karim M. Omambac,
Jessica Afalla,
Deborah Anne Lumantas,
A. Salvador,
Elmer Estacio,
Kohji Yamamoto,
Masahiko Tani
Publication year - 2015
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.23.014532
Subject(s) - terahertz radiation , quantum dot , materials science , spectroscopy , terahertz time domain spectroscopy , optoelectronics , excitation , terahertz spectroscopy and technology , dipole , wavelength , optics , physics , quantum mechanics
We present experimental demonstration of photocarrier dynamics in InAs quantum dots (QDs) via terahertz (THz) time-domain spectroscopy (TDS) using two excitation wavelengths and observing the magnetic field polarity characteristics of the THz signal. The InAs QDs was grown using standard Stranski-Krastanow technique on semi-insulating GaAs substrate. Excitation pump at 800 nm- and 910 nm-wavelength were used to distinguish THz emission from the InAs/GaAs matrix and InAs respectively. THz-TDS at 800 nm pump revealed intense THz emission comparable to a bulk p-InAs. For 910 nm pump, the THz emission generally weakened and upon applying external magnetic field of opposite polarities, the THz time-domain plot exhibited anomalous phase-shifting. This was attributed to the possible current-surge associated with the permanent dipole in the QD.