|Title||Probing dopant incorporation in InAs/GaAs QDIPs by polarization-dependent Fourier transform infrared spectroscopy|
|Publication Type||Journal Article|
|Year of Publication||2007|
|Authors||ZY Zhao, C Yi, AD Stiff-Roberts, AJ Hoffman, D Wasserman, and C Gmachl|
|Journal||Infrared Physics & Technology|
|Pagination||131 - 135|
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.
|Short Title||Infrared Physics & Technology|