3 December 2012 Long-wave type-II superlattice detectors with unipolar electron and hole barriers
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The performance of a long-wave infrared type-II InAs/GaSb superlattice photodetector with a 50% cut-off wavelength of approximately 8.7 μm is presented. The ability to lower dark current densities over traditional P-type-Intrinsic-N-type diodes is offered by way of hetero-structure engineering of a pBiBn structure utilizing superlattice p-type (p) and n-type (n) contacts, an intrinsic (i) superlattice active (absorber) region, and unipolar superlattice electron and hole blocking (B) layers. The spectral response of this pBiBn detector structure was determined using a Fourier transform infrared spectrometer, and the quantum efficiency was determined using a 6250 nm narrow band filter and a 500 K blackbody source. A diode structure designed, grown, and fabricated in this study yielded a dark current density of 1.05×10-5 A/cm2 at a reverse bias of - 50 mV and a specific detectivity value of greater than 1011 Jones at 77 K. Theoretical fittings of the diode dark currents at 77 K were used in this study to help isolate the contributing current components observed in the empirical dark current data. A variable temperature study (80 to 300 K) of the dark current is presented for a diode demonstrating diffusion-limited dark current down to 77 K.
© 2012 Society of Photo-Optical Instrumentation Engineers (SPIE)
Eric A. DeCuir, Eric A. DeCuir, Gregory P. Meissner, Gregory P. Meissner, Priyalal S. Wijewarnasuriya, Priyalal S. Wijewarnasuriya, Nutan Gautam, Nutan Gautam, Sanjay Krishna, Sanjay Krishna, Nibir K. Dhar, Nibir K. Dhar, Roger E. Welser, Roger E. Welser, Ashok K. Sood, Ashok K. Sood, } "Long-wave type-II superlattice detectors with unipolar electron and hole barriers," Optical Engineering 51(12), 124001 (3 December 2012). https://doi.org/10.1117/1.OE.51.12.124001 . Submission:

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