Nature Allows High Sensitivity Thermal Imaging With Type-I Quantum Wells Without Optical Couplers: A Grating-Free Quantum Well Infrared Photodetector With High Conversion Efficiency

Quantum well infrared photodetectors (QWIPs) have facilitated thermal imagers with excellent pixel operability, uniformity and stability. The main disadvantage of the standard QWIP technology is the low conversion efficiency (CE) as a result of weak quantum efficiency (QE) and photoconductive gain inhibiting the utilization of the sensor for low background and/or high frame rate applications. The other problem is the requirement of an optical grating which loses its efficiency with decreasing pixel pitch, as well as limiting the performance of dual-band focal plane array (FPA) due to the wavelength dependence of the diffraction-grating coupling efficiency. The author reports a grating-free 15 mu m pixel pitch 640 x 512 mid-wavelength infrared (MWIR) QWIP FPA constructed with the InP/GaInP/In0.83Ga0.17 As material system with normal incident radiation absorption ability. The pixels yielded peak QE, CE and specific detectivity of 23%, similar to 40% and 1 x 10(11) cmHz(1/2)/W (at similar to 80 K with f/2 optics) in spite of the absence of diffraction grating, substantially high cut-off wavelength (5.8 mu m) and broad spectral response (Delta lambda/lambda(p) = 31%). Together with excellent (uncorrected) responsivity and noise equivalent temperature difference nonuniformities of 5.9% and 17%, the results illustrate tremendous improvement over the performance of the conventional MWIR QWIP FPA exhibiting great potential to revive the QWIP technology especially in dual-band imaging.


Fabrication and characterization of InP based quantum well infrared photodetectors
Torunoğlu, Gamze; Beşikci, Cengiz; Parlak, Mehmet; Department of Micro and Nanotechnology (2012)
Quantum Well Infrared Photodetectors (QWIPs) have the advantages of excellent uniformity and mature material properties. Thanks to these properties, large format and low cost QWIP focal plane arrays (FPAs) can be fabricated. The standard material system used for QWIP FPAs is AlGaAs/GaAs in the long wavelength infrared (LWIR) band. AlGaAs/GaAs material system has some disadvantages such as low quantum and conversion efficiencies under high frame rate and/or low background conditions. These limitations of the...
Lattice-matched AlInAs-InGaAs mid-wavelength infrared QWIPs: characteristics and focal plane array performance
Kaldirim, M.; Arslan, Y.; Eker, S. U.; Beşikci, Cengiz (IOP Publishing, 2008-08-01)
The AlInAs/InGaAs material system is promising for mid-wavelength infrared (MWIR) and multi-band quantum well infrared photodetectors (QWIPs) as a lattice-matched alternative to the strained AlGaAs/InGaAs system. In this paper, we report a large format (640 x 512) AlInAs/InGaAs QWIP focal plane array (FPA) with 4.9 mu m cut-off wavelength and assess the performance of this material system for MWIR QWIP applications at both pixel and large format FPA level. We also experimentally demonstrate that the cut-off...
High Conversion Efficiency InP/InGaAs Strained Quantum Well Infrared Photodetector Focal Plane Array With 9.7 mu m Cut-Off for High-Speed Thermal Imaging
Eker, Suleyman Umut; Arslan, Yetkin; Onuk, Ahmet Emre; Beşikci, Cengiz (Institute of Electrical and Electronics Engineers (IEEE), 2010-02-01)
InP/InGaAs material system is an alternative to AlGaAs/GaAs for long wavelength quantum well infrared photodetectors (QWIPs). We demonstrate a large format (640 x 512) QWIP focal plane array (FPA) constructed with the strained InP/InGaAs material system. The strain introduced to the structure through utilization of In0.48Ga0.52As (instead of In0.53Ga0.47As) as the quantum well material shifts the cut-off wavelength from similar to 8.5 to 9.7 mu m. The FPA fabricated with the 40-well epilayer structure yield...
High-x InP/InxGa1-xAs quantum well infrared photodetector
Beşikci, Cengiz (Elsevier BV, 2018-12-01)
Quantum well infrared photodetector (QWIP) technology is still the only thermal imaging sensor technology providing excellent pixel operability, uniformity and stability together with low production cost and insignificant 1/f noise. The main bottleneck of the standard QWIP technology is the low quantum efficiency and device gain inhibiting the utilization of the sensor for low background and/or high frame rate applications. This manuscript reports unusually high quantum efficiency observed in mid-wavelength...
Broadband LWIR and MWIR metamaterial absorbers with a simple design topology: almost perfect absorption and super-octave band operation in MWIR band
ÜSTÜN, Kadir; Sayan, Gönül (The Optical Society, 2017-07-01)
Infrared absorbers are essential structures in the design of thermal emitters and thermal infrared imagers. In this study, we propose simple topologies of wideband metamaterial absorbers operating in the long-wave infrared or in the mid-wave infrared (MWIR) wavelengths of the electromagnetic spectrum where the atmosphere shows transparent behavior. Suggested metamaterial absorbers are mostly thin structures that consist of three functional layers from top to bottom: a periodically patterned metal layer, a p...
Citation Formats
C. Beşikci, “Nature Allows High Sensitivity Thermal Imaging With Type-I Quantum Wells Without Optical Couplers: A Grating-Free Quantum Well Infrared Photodetector With High Conversion Efficiency,” IEEE JOURNAL OF QUANTUM ELECTRONICS, pp. 0–0, 2021, Accessed: 00, 2021. [Online]. Available: