Abstract
A strain-compensated AlAs/InxGa1-xAs/AlAs/ InyAl1-yAs (x ≈ 0.8, y ≈ 0.5) quantum well infrared photodetector (QWIP) structure was grown by molecular beam epitaxy (MBE). Conditions of exact stoichiometric growth were applied at a temperature of ∼420 °C to produce structures capable of detecting IR radiation in the 2-5 νm mid-infrared spectrum. Double crystal x-ray diffraction (DCXRD) and room temperature photoluminescence (PL) experiments confirmed the excellent structural characteristics of the grown material system. A strong room temperature intersubband absorption peak was observed at a wavelength of 2.16 νm. Current-voltage (I-V) measurements as a function of temperature were carried out to electrically characterize the fabricated QWIP devices yielding devices working under background limited infrared photodetection (BLIP) conditions at 270 K. From the I-V curves, an activation energy of 270 meV at zero bias was extracted. This is in good agreement with a current transport mechanism which is dominated by thermionic emission. Photocurrent measurements were carried out and we demonstrate devices that are capable of working at a temperature as high as 270 K at a wavelength of 2.1 νm. The experimental results are in excellent agreement with the modelled values. © 2006 IOP Publishing Ltd.
| Original language | English |
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| Pages (from-to) | 813-817 |
| Number of pages | 4 |
| Journal | Semiconductor Science and Technology |
| Volume | 21 |
| Issue number | 6 |
| DOIs | |
| Publication status | Published - 1 Jun 2006 |