Probing dopant incorporation in InAs/GaAs QDIPs by polarization-dependent Fourier transform infrared spectroscopy

TitleProbing dopant incorporation in InAs/GaAs QDIPs by polarization-dependent Fourier transform infrared spectroscopy
Publication TypeJournal Article
Year of Publication2007
AuthorsZY Zhao, C Yi, AD Stiff-Roberts, AJ Hoffman, D Wasserman, and C Gmachl
JournalInfrared Physics & Technology
Volume51
Issue2
Start Page131
Pagination131 - 135
Date Published10/2007
Abstract

In order to improve spectral response tunability of quantum-dot infrared photodetectors (QDIPs), it is critical to understand how dopants are incorporated into quantum dots (QDs). In this letter, polarization-dependent Fourier transform infrared spectroscopy is used to measure intraband absorption in InAs/GaAs QDs. Through the investigation of device heterostructures with varying modulation-doped carrier concentrations, we have correlated the charge filling process of energy levels in high-density QD ensembles with IR absorbance spectra. In addition, we have observed the IR signature of a transition originating in deep-level defect centers arising from Si-doped GaAs. © 2007 Elsevier B.V. All rights reserved.

DOI10.1016/j.infrared.2007.04.002
Short TitleInfrared Physics & Technology