MWIR InP/InGaAs quantum well infrared photodetectors

Date

2023-9-8

Author

Balcı, Saadettin Veysel

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In this study, a quantum well infrared photodetector was fabricated to detect mid - wavelength infrared radiation (MWIR). The detector structure was constructed using InP barriers, In0.85Ga0.15As wells, and contact layers. The aim of this study was to exploit the high gain property of the InP material and the direct incident radiation absorption ability of the high-x containing InxGa1-xAs material. In this study, a focal plane array (FPA) and test pixels were fabricated without diffraction grating. The pixel sizes of the fabricated test detectors were 49, 76, 237, 400, and 9x104 µm2. Based on the data obtained from the test detectors, peak quantum efficiency (QE) was 22%. The cut-off wavelength was 6 µm. Conversion efficiency (CE) of ~70% and peak responsivity of 3 A/W were measured at 3.5 V reverse bias. The detector did not exhibit 1/f noise. A peak specific detectivity of 1.5x1011 cm Hz1/2 W-1 was obtained at 78 K operating temperature with an f/2 aperture. In addition, a 15 µm pitch 640x512 format FPA was fabricated and characterized. The mean noise equivalent temperature difference (NETD) was 24 mK at 78 K operating temperature with f/2 optics and 13 ms integration time. The FPA had 99.3% pixel operability and 10.3% NETD non-uniformity. According to characterization results, quantum well photodetectors have the potential to be one of the new generation infrared detector technologies

Subject Keywords

Infrared photodetector, Thermal imaging, Mid-wavelength infrared, Quantum well infrared photodetector

URI

https://hdl.handle.net/11511/105574

Collections

Graduate School of Natural and Applied Sciences, Thesis