Corrugated quantum well infrared photodetectors for far infrared detection

• Published in: Optical Engineering 2011-06, Vol.50 (6), p.061005-061005
• Main Authors: Choi, Kwong-Kit, Sun, Jason, Jhabvala, Merzy D, Forrai, David P, Endres, Darrel W
• Format: Article
• Language: English
• Subjects: Corrugating; Dark current; Density; Detectors; Focal plane; Infrared; Noise equivalent temperature difference; Photodetectors
• ISSN: 0091-3286; 1560-2303; 1560-2303
• DOI: 10.1117/1.3578406

We have extended our investigation of corrugated quantum well infrared photodetector focal plane arrays (FPAs) into the far infrared regime. Specifically, we are developing the detectors for the thermal infrared sensor (TIRS) used in the Landsat Data Continuity Mission. To maintain a low dark current, we adopted a low doping density of 0.6×10 cm and a bound-to-bound state detector. The internal absorption quantum efficiency (QE) is calculated to be 25.4%. With a pixel fill factor of 80% and a substrate transmission of 70.9%, the external QE is 14.4%. To yield the theoretical conversion efficiency (CE), the photoconductive gain was measured and is 0.25 at 5 V, from which CE is predicted to be 3.6%. This value is in agreement with the 3.5% from the FPA measurement. Meanwhile, the dark current is measured to be 2.1×10 A/cm at 43 K. For regular infrared imaging above 8 m, the FPA will have an noise equivalent temperature difference (NETD) of 16 mK at 2 ms integration time in the presence of 260 read noise electrons. The highest operability of the tested FPAs is 99.967%. With the CE agreement, we project the FPA performance in the far infrared regime up to 30 m cutoff.