Abstract
Highly strained quantum cascade laser (QCL) and quantum well infrared photodetector (QWIPs) structures based on InxGa (1-x)As-InyAl(1-y)As(x > 0.8,y < 0.3) layers have been grown by molecular beam epitaxy. Conditions of exact stoichiometric growth were used at a temperature of ∼420°C to produce structures that are suitable for both emission and detection in the 2-5 μm mid-infrared regime. High structural integrity, as assessed by double crystal X-ray diffraction, room temperature photoluminescence and electrical characteristics were observed. Strong room temperature intersubband absorption in highly tensile strained and strain-compensated In0.84Ga 0.16As/AlAs/In0.52Al0.48As double barrier quantum wells grown on InP substrates is demonstrated. Γ-Γ intersubband transitions have been observed across a wide range of the mid-infrared spectrum (2-7 μm) in three structures of differing In 0.84Ga0.16As well width (30, 45, and 80 Å). We demonstrate short-wavelength IR, intersubband operation in both detection and emission for application in QC and QWIP structures. By pushing the InGaAs-InAlAs system to its ultimate limit, we have obtained the highest band offsets that are theoretically possible in this system both for the Γ-Γ bands and the Γ-X bands, thereby opening up the way for both high power and high efficiency coupled with short-wavelength operation at room temperature. The versatility of this material system and technique in covering a wide range of the infrared spectrum is thus demonstrated.
Original language | English |
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Pages (from-to) | 496-502 |
Number of pages | 7 |
Journal | Physica E: Low-Dimensional Systems and Nanostructures |
Volume | 20 |
Issue number | 3-4 |
DOIs | |
Publication status | Published - 1 Jan 2004 |
Event | Proceedings of the 11th International Conference on Narrow Gap - Buffalo, NY., United States Duration: 16 Jun 2003 → 20 Jun 2003 |
Keywords
- Quantum cascade lasers (QCL)
- Quantum well infrared photodetectors (QWIP)
- Strained epitaxy