Effect of contact doping in superlattice-based minority carrier unipolar detectors

B. M. Nguyen*, G. Chen, A. M. Hoang, S. Abdollahi Pour, S. Bogdanov, M. Razeghi

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

37 Scopus citations


We report the influence of the contact doping profile on the performance of superlattice-based minority carrier unipolar devices for mid-wave infrared detection. Unlike in a photodiode, the space charge in the p-contact of a pMp unipolar device is formed with accumulated mobile carriers, resulting in higher dark current in the device with highly doped p-contact. By reducing the doping concentration in the contact layer, the dark current is decreased by one order of magnitude. At 150 K, 4.9 μm cut-off devices exhibit a dark current of 2 × 10-5A/cm2 and a quantum efficiency of 44%. The resulting specific detectivity is 6.2 × 1011 cm Hz 1/2/W at 150 K and exceeds 1.9 × 1014 cm Hz 1/2/W at 77 K.

Original languageEnglish (US)
Article number033501
JournalApplied Physics Letters
Issue number3
StatePublished - Jul 18 2011

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)


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