InAs/InAs1−xSbx type-II superlattices for high performance long wavelength infrared detection

Haddadi, Abbas; Chen, G.; Chevallier, Romain; Hoang, A. M.; Razeghi, Manijeh

doi:10.1063/1.4896271

Cited by 102 publications

(48 citation statements)

References 14 publications

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“…It is believed that hole mobility in an n-type T2SL should be very low because of the exceedingly large vertical (growth-direction) hole effective mass [11]. Yet ntype T2SL based detectors have demonstrated very satisfactory optical responses experimentally [27,28,29]. We will show that a closer inspection of the T2SL band structure offers a possible explanation for why the hole mobility may not be as poor as suggested by the simple band-edge effective mass picture.…”

Section: Superlattice Hole Effective Massmentioning

confidence: 95%

Carrier transport in unipolar barrier infrared detectors

et al. 2015

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We examine carrier transport in unipolar barrier infrared photodetectors and discuss aspects of barrier, contact, and absorber properties that can affect minority carrier collection. In a barrier infrared detector the unipolar barrier should block only the majority carriers while allowing the un-impeded flow of the minority carriers. Under the right conditions, unipolar barrier doping can reduce generation-recombination dark current without affecting minority carrier extraction. In an nBn structure, ideally with an electron unipolar barrier, improper barrier doping or barrier-absorber valence band offset could also block minority carriers and result in higher turn-on bias. We also examined the temperature-dependent turn-on bias in an n + Bn device and showed that observed behavior may be attributed to contact doping. Hole mobility in n-doped type-II superlattice (T2SL) is believed to be very low because of the extremely large effective mass along the growth direction. In practice MWIR and LWIR barrier infrared detectors with n-type T2SL absorbers have demonstrated good optical response. A closer inspection of the T2SL band structure offers a possible explanation as to why the hole mobility may not be as poor as suggested by the simple effective mass picture.

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Section: Superlattice Hole Effective Massmentioning

confidence: 95%

Carrier transport in unipolar barrier infrared detectors

et al. 2015

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“…11 Yet, experimentally, n-type T2SL detectors have very satisfactory optical responses. [22][23][24] We will show that closer inspection of the T2SL band structure suggests a possible reason why hole mobility may not be as poor as suggested by the simple band-edge effective mass hypothesis.…”

Section: Introductionmentioning

confidence: 95%

Theoretical Aspects of Minority Carrier Extraction in Unipolar Barrier Infrared Detectors

Ting

Soibel

Höglund

et al. 2015

Journal of Elec Materi

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We have examined, theoretically, minority carrier collection in unipolar barrier infrared photodetectors. In barrier infrared detectors, for example the nBn, the unipolar barrier should block only majority carriers and allow unimpeded flow of minority carriers. However, an imperfect barrier would also block minority carriers, resulting in higher than expected turn-on bias. Minority carrier blocking can be caused by barrier doping or unintended band offset between the barrier and the absorber. The distinct manner in which these two mechanisms affect device performance were investigated. We found that introduction of an appropriate amount of barrier doping can reduce depletion dark current without increasing turn-on bias. We examined the effects of band structure on conductivity effective masses when the n-type absorber was a type-II superlattice (T2SL). We showed that for a long-wavelength infrared InAs/GaSb T2SL the vertical conductivity hole effective mass can be much smaller than that predicted by the simple band-edge effect mass picture, implying that the vertical hole mobility estimated from the band-edge effective mass can be unduly pessimistic.

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“…This G-R current arises from a low Shockley-ReadHall (SRH) carrier lifetime [3][4][5], which is currently attributed to native defects in the GaSb layer [6]. The InAs-InAsSb (Ga-free) SL was developed to avoid the low lifetimes associated with the GaSb layer, and has shown significant improvement in SRH carrier lifetimes [7][8][9][10]. This is expected to result in improved performance in infrared detectors made from this material.…”

Section: Introductionmentioning

confidence: 98%