scholarly journals InAs/InAsSb Strained-Layer Superlattice Mid-Wavelength Infrared Detector for High-Temperature Operation

Micromachines ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 806 ◽  
Author(s):  
Gamini Ariyawansa ◽  
Joshua Duran ◽  
Charles Reyner ◽  
John Scheihing

This paper reports an InAs/InAsSb strained-layer superlattice (SLS) mid-wavelength infrared detector and a focal plane array particularly suited for high-temperature operation. Utilizing the nBn architecture, the detector structure was grown by molecular beam epitaxy and consists of a 5.5 µm thick n-type SLS as the infrared-absorbing element. Through detailed characterization, it was found that the detector exhibits a cut-off wavelength of 5.5 um, a peak external quantum efficiency (without anti-reflection coating) of 56%, and a dark current of 3.4 × 10−4 A/cm2, which is a factor of 9 times Rule 07, at 160 K temperature. It was also found that the quantum efficiency increases with temperature and reaches ~56% at 140 K, which is probably due to the diffusion length being shorter than the absorber thickness at temperatures below 140 K. A 320 × 256 focal plane array was also fabricated and tested, revealing noise equivalent temperature difference of ~10 mK at 80 K with f/2.3 optics and 3 ms integration time. The overall performance indicates that these SLS detectors have the potential to reach the performance comparable to InSb detectors at temperatures higher than 80 K, enabling high-temperature operation.

Micromachines ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 958 ◽  
Author(s):  
David Z. Ting ◽  
Sir B. Rafol ◽  
Arezou Khoshakhlagh ◽  
Alexander Soibel ◽  
Sam A. Keo ◽  
...  

The InAs/InAsSb (Gallium-free) type-II strained-layer superlattice (T2SLS) has emerged in the last decade as a viable infrared detector material with a continuously adjustable band gap capable of accommodating detector cutoff wavelengths ranging from 4 to 15 µm and beyond. When coupled with the unipolar barrier infrared detector architecture, the InAs/InAsSb T2SLS mid-wavelength infrared (MWIR) focal plane array (FPA) has demonstrated a significantly higher operating temperature than InSb FPA, a major incumbent technology. In this brief review paper, we describe the emergence of the InAs/InAsSb T2SLS infrared photodetector technology, point out its advantages and disadvantages, and survey its recent development.


2018 ◽  
Vol 113 (2) ◽  
pp. 021101 ◽  
Author(s):  
David Z. Ting ◽  
Alexander Soibel ◽  
Arezou Khoshakhlagh ◽  
Sir B. Rafol ◽  
Sam A. Keo ◽  
...  

Author(s):  
David Z. Ting ◽  
Alexander Soibel ◽  
Arezou Khoshakhlagh ◽  
Sam A. Keo ◽  
Sir B. Rafol ◽  
...  

2018 ◽  
Vol 72 (2) ◽  
pp. 177-187 ◽  
Author(s):  
Sara Kirchner ◽  
Sebastien Narinsamy ◽  
Alain Sommier ◽  
Marta Romano ◽  
Meguya Ryu ◽  
...  

The purpose of this article is to present a new calibration procedure for spectroscopic measurements using an infrared focal plane array (IRFPA) spectrometer on highly opaque middle-wave infrared (MWIR) media. The procedure is based on the properties of the IRFPA camera and especially the integration time (IT), which is the main parameter that can be adjusted to control the sensitivity of the measurements. The goal of the paper is to experimentally validate this dependence with the direct reference intensity light coming out of the IR monochromator in order to predict the spectrum shape and intensity level in a range out of the camera saturation. This method allows determining spectrum used as background for transmittance calculation. It has been applied in the case of measurement of water transmittance, which is a highly opaque medium and whose measurement requires high ITs. The main result is the ability to take an IR spectroscopic imaging measurement through 300 µm of water and the determination of its transmittance with sufficient sensitivity due to the proposed calibration procedure. This procedure allows the possibility of transitory studies in heterogeneous aqueous media.


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