Advances in Infrared Detector Array Technology

Dhar, Nibir K.; Dat, R.; Sood, Ashok K.

doi:10.5772/51665

Cited by 20 publications

(5 citation statements)

References 78 publications

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“…Detectors and imaging arrays operating over the visible spectrum (~400-700 nm) are mostly Si-based, consisting of charge-coupled device (CCD) imagers and complementary metal oxide semiconductor (CMOS) technologies. For detection of infrared (IR) wavelengths invisible to the human eye, which span the range of approximately 1.0 μm in the near-infrared (NIR) to beyond 30 μm, other materials and technologies are required [3].…”

Section: Introductionmentioning

confidence: 99%

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Nanostructure Technology for EO/IR Detector Applications

Sood¹,

Zeller²,

Pethuraja³

et al. 2020

Nanorods and Nanocomposites

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This chapter covers recent advances in the development of nanostructurebased material technologies to benefit next-generation electro-optical (EO) and infrared (IR) sensor and imager applications. Nanostructured materials can now be integrated into a variety of technological platforms, offering novel optoelectrical properties that greatly enhance device performance in many practical applications. Use of novel carbon nanotube (CNT) based materials has enabled new approaches for applying nanostructure design methodologies that can offer enhanced performance for low-cost bolometers for IR detection and imaging applications. We will discuss the development of carbon nanostructure based infrared detectors and arrays, including concepts that will provide high performance, high frame rate, and uncooled microbolometers for mid-wave infrared (MWIR) and long-wave infrared (LWIR) band detection. In addition, nanostructured antireflection (AR) coatings are being developed that significantly enhance transmission over a broad spectrum, providing substantial improvements in device performance compared to conventional thin film AR coatings. These nanostructured AR coatings have been demonstrated over visible to LWIR spectral bands on various substrates. In this chapter, we discuss both theoretical and measured results of these diverse nanostructure technologies to advance sensing performance over a wide range of spectral bands for defense, space, and commercial applications.

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Section: Introductionmentioning

confidence: 99%

“…To address this, nanostructured antireflection (AR) coatings have been developed to reduce unwanted reflections and increase the transmission of light from visible to LWIR wavelengths, thereby improving detector performance [9,10]. IR spectral band atmospheric windows [3].…”

Section: Introductionmentioning

confidence: 99%

Nanostructure Technology for EO/IR Detector Applications

Sood¹,

Zeller²,

Pethuraja³

et al. 2020

Nanorods and Nanocomposites

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“…36 Nevertheless, InGaAs short wavelength infrared (SWIR) detectors are preferred due to having low dark current and noise and operating at room temperature. 37,38 In addition, InGaAs/InP MSM devices can operate for infrared imaging in the medium wavelength infrared (MWIR) and long wavelength infrared (LWIR) bands at room temperature. 39 In spite of having easy band gap tailoring, well developed theory and experiment, InGaAs detectors which have good materials, dopants, advanced technology, and possible monolithic integration have been preferred.…”

Section: Introductionmentioning

confidence: 99%

Structural and electrical characterizations of InxGa1-xAs/InP structures for infrared photodetector applications

Asar

Özçelik

Özbay

2014

Journal of Applied Physics

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Three InGaAs/InP structures for photodetector applications were grown with different indium compositions by MBE technique. The structural properties of the samples have been obtained by means of high resolution X-ray diffraction and secondary ion mass spectrometry measurements. Three InGaAs/InP metal-semiconductor-metal devices were fabricated at room temperature. The experimental forward and reverse bias current–voltage characteristics of the devices such as ideality factor, barrier height, and saturation current were evaluated considering the structural properties of the grown structures. The carrier recombination lifetime and diffusion length in the devices were also calculated using carrier density and mobility data obtained with Hall effect measurement at room temperature. It was determined that all room temperature fabricated devices improved the Schottky barrier height. Especially, the device fabricated on the lower mismatched structure exhibited barrier height enhancement from 0.2 eV, which is the conventional barrier height to 0.642 eV. In addition, the obtained results show that the room temperature fabricated devices on InGaAs/InP structures can be convenient for infrared photodetector applications.

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“…To create a two colour detector, where the transducer, rather than the window gives spectral selectivity, requires the use of two unique material compositions. Both must have different lattice constants and material parameters, doubling the cost and severely increasing the complexity of device design [9].…”

Section: Photodetection Conceptsmentioning

confidence: 99%

“…2. Collision detection and imaging systems that are not affected by ambient particulate or light conditions [8,9].…”

Section: Introductionmentioning

confidence: 99%

Device Applications of Solution Processed MIR Semiconductor Nanocrystal Thin Films

Cryer¹

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<p>Colloidal semiconductor nanocrystals (NCs) with bandgaps less than 1 eV allow the development of mid wave infrared (MIR) sensitive detectors that exploit the benefits of colloidal materials, primarily bandgap selection and solution deposition. Additionally, the electrical behaviour of these films can be examined for characteristics that can increase the functionality of NC based detectors. The production of devices that are designed to be competitive as ultra-low-cost, room temperature MIR detectors, operating with photonic, rather than thermal detection is detailed. The evolution of the colloidal synthesis, spray deposition methods, substrate materials and post deposition treatments used here lead to highly robust and high performing devices. These devices demonstrate a “colour” sensitivity down to 300 nm in the MIR (≈10 % of scale), with superior responsivities for this class of device, up to 0.9 AW⁻¹, and competitive specific detectivity up to 8 × 10⁹ Jones at 200 Hz and 300 K. Furthermore, these devices utilise a cheap and robust substrate material that allows operation after deformation up to 45 ° without degradation over many cycles. These devices offer a template for ultra-low-cost MIR detectors with performance that rivals microbolometers but with better measurement speed and spectral sensitivity. As such these devices showcase the key advantages of using colloidal NCs in MIR applications. Planar and fully air processed thin film devices that demonstrate photo-induced memristive behaviour and can be used as a transistors, photode-tectors or memory devices are investigated. Following long term (60 h) air exposure, unpackaged NC films develop reliable memristive characteristics in tandem with temperature, gate and photoresponse. On/off ratios of more than 50 are achieved and the devices show long term stability, producing repeatable metrics over days of measurement. The on/off behaviour is shown to be dependent on previous charge flow and carrier density, implying memristive rather than switching behaviour. These observations are described within a long term trap filling model. This work represents an advance in the integration of NC films into electronic devices, which may lead to the development of multi-functional electronic components. Building on the previous work the steps taken to move from a planar device, that works well in controlled conditions, to a multi-pixel sensor that can demonstrate MIR video imaging at room temperature in a noisy environment are shown. This is achieved with a 15 pixel detector that consists only of a polymer substrate and solution patterned NC pixels. This device can detect a 373 K object with the device at 298 K in a noisy environment. This performance is enabled by photogain at 5 V bias that reaches a maximum External Quantum Efficiency (EQE) of 1940 ± 290 % for a pixel with a 3.3 µm bandgap. Through the use of four separate bandgaps it is shown that “multicolour” thermal imaging systems can deliver another layer of information, on top of intensity, to the user. The behaviour of the system is examined under use and it is shown that the photoconductive device behaves as expected with regards to bias, and that trap enabled gain is sensitive to total incident flux, more than the spectral energy distribution of the target. Finally, it is shown that solution patterned QD fabrication methods can deliver electrical reproducibility between pixels that is sufficient to allow an imaging plane of multiple pixels. The somewhat neglected tin chalcogenide semiconductor nanocrystals are investigated and inverse MIR detection at room temperature is demonstrated with planar, solution and airprocessed PbSnTe and SnTe QD devices. The detection mechanism is shown to be mediated by an interaction between MIR radiation and the vibrational stretches of adsorbed hydroxyl species at the oxdised NC surface. Devices are shown to possess mAW⁻¹ responsivity via a reduction in film conductance due to MIR radiation and, unlike classic MIR photoconductors, are unaffected by visible wavelengths. As such these devices offer the possibility of MIR thermal imaging that has an intrinsic solution to the blinding caused by higher energy light sources. In summary, it is shown that semiconductor NCs with an all ambient fully solution processed deposition and ligand exchange procedure can be used to create simple, robust and cheap devices that are beginning to demonstrate metrics on par with current commercial thermal detector systems. It is also shown that these devices can under certain circumstances demonstrate novel behaviours that offer the prospects of enhanced or novel functionality.</p>

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Advances in Infrared Detector Array Technology

Cited by 20 publications

References 78 publications

Nanostructure Technology for EO/IR Detector Applications

Nanostructure Technology for EO/IR Detector Applications

Structural and electrical characterizations of InxGa1-xAs/InP structures for infrared photodetector applications

Device Applications of Solution Processed MIR Semiconductor Nanocrystal Thin Films

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