Resonant Cavity Infrared Detector with Five Quantum-well Absorber and 34% External Quantum Efficiency at 4 Micro(meters)
Journal Article - Open Access
Naval Research Laboratory Washington United States
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We report resonant-cavity infrared detectors with 34 external quantum efficiency at room temperature at the resonant wavelength of 4.0 mu m, even though the absorber consists of only five quantum wells with a total thickness of 50 nm. The full width at half maximum FWHM linewidth is 46 nm, and the peak absorption is enhanced by nearly a factor of 30 over that for a single pass through the absorber. In spite of an unfavorable Shockley-Read lifetime in the current material, the dark current density is at the level of state-of-the-art HgCdTe detectors as quantified by Rule 07. The Johnson-noise limited detectivity D at 21 degrees C is 7 x 109 cm Hz12W. We expect that future improvements in the device design and material quality will lead to higher quantum efficiency, as well as a significant reduction of the dark current density consistent with the very thin absorber.