Papers Published
- Z. Y. Zhao and C. Yi and A. D. Stiff-roberts and A. J. Hoffman and D. Wasserman and C. Gmachl, Probing dopant incorporation in InAs/GaAs QDIPs by polarization-dependent Fourier transform infrared spectroscopy,
Infrared Physics & Technology, vol. 51 no. 2
(October, 2007),
pp. 131 -- 135 .
(last updated on 2008/10/16)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. (c) 2007 Elsevier B.V. All rights reserved.