GaAs/AlGaAs quantum well photodetectors with a cutoff

wavelength at 28 µm

A. G. U. Perera, W. Z. Shen, and S. G. Matsik

Department of Physics and Astronomy, Georgia State University, Atlanta, Georgia 30303

H. C. Liu and M. Buchanan

Institute for Microstructural Sciences, National Research Council, Ottawa K1A 0R6, Canada

W. J. Schaff

School of Electrical Engineering, Cornell University, Ithaca, New York 14853

Abstract

We demonstrate the longest (_c=28.6 µm) far-infrared quantum well photodetectors (QWIPs) based on a bound-to-bound intersubband transition in GaAs/AlGaAs. The responsivity is comparable with that of mid-infrared GaAs/AlGaAs and InGaAs/GaAs QWIPs. A peak responsivity of 0.265 A/W and detectivity of 2.5*10⁹ cm/W at a wavelength of 26.9 µm and 4.2 K have been achieved. Based on the temperature dependent dark current and responsivity results, it is expected that similar performance can be obtained at least up to 20 K.

©1998 American Institute of Physics.

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