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.
Original language | English (US) |
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Pages (from-to) | 131-135 |
Number of pages | 5 |
Journal | Infrared Physics and Technology |
Volume | 51 |
Issue number | 2 |
DOIs | |
State | Published - Oct 2007 |
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics
Keywords
- Deep-level defect center
- Doping
- Fourier transform infrared spectroscopy
- Polarization-dependent absorbance spectrum
- Quantum-dot infrared photodetector