C-QWIP material design and growth

We are developing corrugated quantum well infrared photodetector (C-QWIP) technology for long wavelength applications. A number of large format 1024 × 1024 C-QWIP focal plane arrays (FPAs) have been demonstrated. The measured quantum efficiency η is ranging from 15 -37%, depending on the detector type, doping density and number of quantum wells in the detector material. The photoconductive gain is between 0.07 and 0.19, while the spectral width is between 1.5 and 3.5 microns. Despite the large integrated η of the C-QWIPs, the number of collected photoelectrons can be limited in shorter cutoff, small pixel FPAs under high speed operation. In this case, the read noise will have a large impact on the system sensitivity. In this paper, we will discuss the detector model, the measured pixel characteristics, and the effects of read noise on the FPA performance. Our analysis shows that the tolerable read noise improves with the cutoff wavelength. For example, to achieve a sensitivity of 20 mK at 2 msec integration time, the respective read noise will be 1000, 2000, 3000, and 4000 e¯ at λ c = 8. 8, 9.4, 10.7 and 11.7 μm. This analysis will help to determine the read noise requirement for the C-QWIP FPAs.

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“…The quantum efficiency η of a C-QWIP has been discussed in detail in the past [2]. It can be calculated in a straightforward manner.…”

Section: C-qwip Quantum Efficiencymentioning

confidence: 99%

“…However, due to their limited quantum efficiency and bandwidth, high sensitivity is achieved only at the expense of the detection speed. In order to reduce the integration time, the corrugated-QWIP structure was proposed and investigated [1,2,3,4]. In this paper, we will review and summarize these results.…”

Section: Introductionmentioning

confidence: 98%

C-QWIP focal plane array sensitivity

et al. 2009

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“…A new light coupling scheme is thus needed. Recently, an efficient broadband light coupling based on the corrugated QWIPs (C-QWIPs) has been demonstrated [7]. Based on angled sidewall reflections, this detector geometry preserves the intrinsic absorption properties of the QWIP materials [8], and thus, it is particularly suitable for the present application.…”

Section: Introductionmentioning

confidence: 99%

Voltage-Tunable Two-Color Corrugated-QWIP Focal Plane Arrays

Choi

Jhabvala

Peralta

2008

IEEE Electron Device Lett.

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We demonstrated a 256 × 256 voltage-tunable twocolor corrugated quantum-well infrared-photodetector focal plane array. The detector operation is based on photocurrent asymmetry in a double-superlattice quantum well structure. By using a broadband corrugated light coupling scheme, we obtained a quantum efficiency of 24% in the mid-wave (MW) band and 26% in the long-wave (LW) band without AR coating. Operating at 50 K, the measured noise equivalent temperature difference is 27 mK at 33-ms integration time for the MW and 90 mK at 2 ms for the LW with f/2.44 optics. The NETD operability values are 98.4% and 95.9%, respectively.Index Terms-Infrared detectors, infrared image sensors, quantum wells.

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“…This type of analysis has been conducted in the past, such as that based on the corrugated-QWIP structure. 1 Recently, we have advanced a new detector structure, which is known as the resonator-QWIP or R-QWIP. 2 The R-QWIP uses a thin, lightly doped resonator structure to achieve a high quantum efficiency (QE) and a large photoconductive gain g. Its performance characteristics are significantly different from the conventional QWIP structures in terms of QE, g, and the photocurrent to dark current ratio, r. It is therefore worthwhile to conduct another analysis based on the new structure.…”

Section: Introductionmentioning

confidence: 99%

“…In this analysis, we will use the detector temporal NEΔT as the figure of merit given by (1) In Eq. (1), C is the thermal contrast and N tot is the total number of electrons collected in τ int .…”

Section: Introductionmentioning

confidence: 99%

Resonator-QWIP FPA development

2015

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Previously, we adopted the resonator-QWIPs and increased the FPA QE to 30 − 40%. In this work, we performed a systematic theoretical analysis on the potential performance based on this new detector structure. In this analysis, the doping density and the number of quantum wells are varied to obtain different detector characteristics. For 25 μm pixel pitch, 10 Me − integrated charge, and F/2 optics, the analysis shows that a 9.2 μm cutoff R-QWIP optimized for high temperature operation could provide 20 mK NEΔT at τ int = 2.6 ms when operating at T = 80 K. An R-QWIP with a 10.2 μm cutoff could achieve the same with τ int = 1.3 ms at T = 74 K. Similar NEΔT can also be achieved with smaller pixel pitch down to 6 μm for both cutoffs with a more relaxed operating condition where the f-number is 1, τ int is 5 ms, and T is 70 K. We provide preliminary test detector data to support this analysis.

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C-QWIP material design and growth

Cited by 6 publications

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C-QWIP focal plane array sensitivity

C-QWIP focal plane array sensitivity

Voltage-Tunable Two-Color Corrugated-QWIP Focal Plane Arrays

Resonator-QWIP FPA development

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