Room Temperature MWIR Infrared Detectors and Arrays for High Dynamic Range IR Imaging

Current MWIR focal plane arrays require a minimum of 140K cooling. This cooling requirement makes this incumbent technology’s size, weight, power, and cost (SWaP-C) too high such that it is mostly limited to military applications. This also limits widespread deployment and MWIR applications on smaller platforms within the defense domain. Our proposed effort, that is supported by our past work, offers a new technology that will be capable of room temperature MWIR focal plane array operation, making it more affordable and portable, enabling widespread application within the Department of Defense with particular advantage for the Air Force utilizing smaller platforms (Drones etc.). In addition, this proposed MWIR technology will also be able to enter the commercial market because of the low SWaP-C. In this work we propose a Field Effect, low doped 2D channel enhanced detector (see Figure 5 in the technical volume) using an enhancement mode FET operation that has the following technical features:The channel modulation due to photogeneration can be significantly higher, thus increasing the response dynamic range and sensitivity at lower gate bias leading to higher performance.The low doped channel isolation from the HgCdTe absorber layer (See Figure 5) creates separate charge action (in 2D channel) and Photogeneration in HgCdTe. This is interesting because the Auger and SRH noise current do not play a role as the charge action is separated from the absorber. The electric field aids the charge pump that drives the carriers to populate the channel from source in concert with the photogeneration rather than charge injected from the absorber as was the case in our original design discussed in the technical volume.Transconductance gain boosting SNR. The FET design naturally offers gain through transconductance across the channel. Based on our initial work where we developed a depletion mode FET, we learned that an enhancement mode FET design will meet the SBIR requirements for this direct to Phase II project. We have already demonstrated a D* value of 1x1010 Jones. We will be using low doped channel material to demonstrate an enhancement mode phototransistor design, which will achieve performance on par with the state-of-the-art MWIR technology, but at room temperature.