Abstract
Design of practically realizable unipolar HgCdTe nBn photodetectors has been studied in detail by numerical analysis. The simulations reported herein reveal that, by optimization of barrier doping, dark current levels can be reduced and collection efficiency substantially improved. It is shown that p-type doping of the barrier layer can significantly reduce the effective potential barrier arising from the valence band offset between the absorber and barrier regions, thus enabling HgCdTe nBn detector operation under near zero-bias conditions. However, relatively high electric fields in the space charge regions near the barrier/absorber interface result in enhanced trap-assisted Shockley–Read–Hall thermal generation. Our calculations indicate that nBn HgCdTe detectors with barriers engineered by use of HgTe/Hg0.05Cd0.95Te superlattices have, potentially, substantially better valence band alignment without the need for p-type doping.
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References
S. Maimon and G.W. Wicks, Appl. Phys. Lett. 89, 151109 (2006).
P. Klipstein, Proc. SPIE. 6940, 69402U-1 (2008).
D. Ting, A. Soibel, C. Hill, S. Keo, J. Mumolo, and S. Gunapala, Proc. SPIE 8353, 835332 (2012).
E. Plis, S. Myers, M.N. Kutty, J. Mailferd, E.P. Smith, S. Johnson, and S. Krishna, Appl. Phys. Lett. 97, 123503 (2010).
J.B. Rodriguez, E. Plis, G. Bishop, Y.D. Sharma, H. Kim, L.R. Dawson, and S. Krishna, Appl. Phys. Lett. 91, 043514-1 (2007).
A.M. Itsuno, J.D. Phillips, and S. Velicu, Appl. Phys. Lett. 100, 161102 (2012).
A.M. Itsuno, J.D. Phillips, and S. Velicu, J. Electron. Mater. 41, 2886 (2012).
S. Velicu, J. Zhao, M. Morley, A.M. Itsuno, and J.D. Philips, Proc. SPIE 8268, 82682X-1 (2012).
P. Maryniuk and A. Rogalski, Solid-State Electron. 80, 96104 (2013).
A. Jóźwikowska, J. Appl. Phys. 104, 063715 (2008).
G. Bastard, Phys. Rev. B 25, 7584 (1982).
F. Szmulowicz, E.R. Heller, K. Fisher, and F.L. Madarasz, Superlattices Microstruct. 17, 373 (1995).
P.M. Hui, H. Ehrenreich, and N.F. Johnson, J Vac Sci Technol A 7, 424 (1989).
N.F. Johnson, P.M. Hui, and H. Ehrenreich, Phys. Rev. Lett. 61, 1993 (1988).
R. Sporken, S. Sivananthan, J.P. Faurie, D.H. Ehlers, J. Fraxedas, L. Ley, J.J. Pireaux, and R. Caudano, J. Vac. Sci. Technol. A 7, 427 (1989).
D. Eich, K. Ortner, U. Groh, Z.H. Chen, C.R. Becker, G. Landwehr, R. Fink, and E. Umbach, Phys. Stat. Sol. (a) 173, 261 (1999).
C.R. Becker, V. Latussek, A. Pfeuffer-Jeschke, G. Landwehr, and L.W. Molenkamp, Phys. Rev. B 62, 10353 (2000).
K.H. Yoo, R.L. Aggarwal, L.R. Ram-Mohan, and O.K. Wu, J. Vac. Sci. Technol. A 8, 1194 (1990).
Z. Yang, Z. Yu, Y. Lansari, S. Hwang, J.W. Cook Jr, and J.F. Schetzina, Phys. Rev. B 49, 8096 (1994).
N.F. Johnson, H. Ehrenreich, P.M. Hui, and P.M. Young, Phys. Rev. B 41, 3655 (1990).
G. Bastard, Wave mechanics applied to semiconductor heterostructures, (Les Éditions de Physique, Les Ulis, 1988).
M.H. Weiler, Semiconductors and Semimetals, vol. 16, ed. R.K. Willardson and A.C. Beer, (Academic Press, New York, 1981), p. 119.
G.L. Hansen, J.L. Schmit, and T.N. Casselman, J. Appl. Phys. 53, 7099 (1982).
The Material Libraries in Commercial Program, Semicad Devices V.1.2, Down Technologies 1994.
K. Jóźwikowski, M. Kopytko, and A. Rogalski, J. Appl. Phys. 112, 033718 (2012).
Acknowledgements
The work was supported financially by Polish National Science Centre research Project No. DEC-2013/08/M/ST7/00913, Australian Research Council projects DP120104835 and FS110200022, and the WA-node of the Australian National Fabrication Facility.
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Kopytko, M., Wróbel, J., Jóźwikowski, K. et al. Engineering the Bandgap of Unipolar HgCdTe-Based nBn Infrared Photodetectors. J. Electron. Mater. 44, 158–166 (2015). https://doi.org/10.1007/s11664-014-3511-9
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DOI: https://doi.org/10.1007/s11664-014-3511-9