A high-sensitivity In_0.6Ga_0.4As/GaAs quantum-dot infrared photodetector (QDIP) with detection waveband in 6.7 to approximately 11.5 μm and operating temperature up to 260K under normal incident illumination has been demonstrated. The peak detection wavelength shifts from 7.6 μm to 8.4 μm when the temperature rises from 40 to 260K. The background limited performance (BLIP) detectivity (D*_BLIP) measured at V_b=1.5 V, T=77K and λ_p = 7.6 μm was found to be 1.25 x 10¹⁰ cm-Hz^1/2/W, with a corresponding responsivity of 0.22A/W. The high operating temperature is attributed to the very low dark current and long carrier lifetime in the quantum dots of this device. The results show that this QDIP can operate at high temperature without using the large band gap material such as AlGaAs or InGaP as blocking barrier to reduce the device dark current.

Date Published: 10 October 2003
PDF: 8 pages
Proc. SPIE 5074, Infrared Technology and Applications XXIX, (10 October 2003); doi: 10.1117/12.487034

Published in SPIE Proceedings Vol. 5074:
Infrared Technology and Applications XXIX
Bjorn F. Andresen; Gabor F. Fulop, Editor(s)