InAsSb detectors for visible to MWIR high-operating temperature applications

A. I. D'Souza; A. C. Ionescu; M. Salcido; E. Robinson; L. C. Dawson; D. L. Okerlund; T. J. de Lyon; R. D. Rajavel; H. Sharifi; D. Yap; M. L. Beliciu; S. Mehta; W. Dai; G. Chen; N. Dhar; P. Wijewarnasuriya

doi:10.1117/12.884550

Translator Disclaimer

20 May 2011 InAsSb detectors for visible to MWIR high-operating temperature applications

A. I. D'Souza, A. C. Ionescu, M. Salcido, E. Robinson, L. C. Dawson, D. L. Okerlund, T. J. de Lyon, R. D. Rajavel, H. Sharifi, D. Yap, M. L. Beliciu, S. Mehta, W. Dai, G. Chen, N. Dhar, P. Wijewarnasuriya

Author Affiliations +

Proceedings Volume 8012, Infrared Technology and Applications XXXVII; 80122S (2011) https://doi.org/10.1117/12.884550
Event: SPIE Defense, Security, and Sensing, 2011, Orlando, Florida, United States

Abstract

The Photon-Trap Structures for Quantum Advanced Detectors (PT-SQUAD) program requires MWIR detectors at 200 K. One of the ambitious requirements is to obtain high (> 80 %) quantum efficiency over the visible to MWIR spectral range while maintaining high D* (> 1.0 x 10¹¹ cm √Hz/W) in the MWIR. A prime method to accomplish the goals is by reducing dark diffusion current in the detector via reducing the volume fill ratio (VFR) of the detector while optimizing absorption. Electromagnetic simulations show that an innovative architecture using pyramids as photon trapping structures provide a photon trapping mechanism by refractive-index-matching at the tapered air/semiconductor interface, thus minimizing the reflection and maximizing absorption to > 90 % over the entire visible to MWIR spectral range. InAsSb with bandgap appropriate to obtaining a cutoff wavelength ~ 4.3 μm is chosen as the absorber layer. An added benefit of reducing VFR using pyramids is that no AR-coating is required. Compound-barrier (CB) detector test structures with alloy composition of the InAsSb absorber layer adjusted to achieve 200 K cutoff wavelength of 4.3 μm (InAsSb lattice-matched to GaSb). Dark current density at 200 K is in the low 10^-4 A/cm² at V_d = -1.0 V. External QE ~ 0.65 has been measured for detectors with a Si carrier wafer attached. Since illumination is through the Si carrier wafer that has a reflectance of ~ 30 %, this results in an internal QE > 0.9.

Citation Download Citation

A. I. D'Souza, A. C. Ionescu, M. Salcido, E. Robinson, L. C. Dawson, D. L. Okerlund, T. J. de Lyon, R. D. Rajavel, H. Sharifi, D. Yap, M. L. Beliciu, S. Mehta, W. Dai, G. Chen, N. Dhar, and P. Wijewarnasuriya "InAsSb detectors for visible to MWIR high-operating temperature applications", Proc. SPIE 8012, Infrared Technology and Applications XXXVII, 80122S (20 May 2011); https://doi.org/10.1117/12.884550

ACCESS THE FULL ARTICLE