The temperature dependence of the dark current in InAsSb-based p – n photodiodes detecting radiation in the medium-wave infrared (MWIR) region have been calculated, taking into account material characteristics of InAs 1 – x Sb x alloy. The desired signal-to-noise ratio is ∼10 3 at T = 150 K, which confirms the possibility of achieving high photovoltaic parameters in InAs 1 – x Sb x photodiodes and their usage in high-temperature applications.

Multilayer structures based on the antimonide group materials with absorber layers InSb or AlxIn1-XSb, and XBn-structures with AlxIn1-XSb barrier layer (InSb/AlxIn1-XSb/InSb), designed for the manufacture of advanced photosensitive devices detecting radiation in the medium-wave infrared (IR) range (MWIR), have been developed and investigated. Various topology photosensitive elements (PSE) with absorbing layers InSb or AlxIn1-XSb were fabricated on the basis of MBE-grown p–i–n and barrier structures. It is shown that wideband ternary al-loys AlxIn1-XSb are considered as an alternative to the narrowband binary compound InSb, since, due to wide-band material properties, photodiodes based on AlxIn1-XSb have lower dark currents, and, consequently, noise. The average values of detectivity D* and noise-equivalent temperature difference (NETD) have been measured for various topology photodetectors, so D* was more than 1011 cmW-1Hz1/2 in p–i–n-structures, and D* exceed of 1012 cmW-1Hz1/2 in barrier structures.

A ternary solution of mercury–cadmium–telluride (MCT, HgCdTe) is one of the few semiconductor materials used to design photodiodes with high parameters. An estimated calculation of the parameters of a promising P+-ν(π)-N+-photodiode structure based on MCT that is designed to build arrays of photosensitive elements (PSEs) with a low dark current was carried out. The dark current is reduced by using an improved three-layer architecture consisting of highly doped MCT contact layers, between which there is a lightly doped absorbing layer, in which thermal generation-recombination processes are suppressed. Thus, in a specified spectral range, the dark currents of PSEs based on the three-layer MCT architecture decrease to the limit set by the background radiation and the radiative recombination mechanism and, under the condition of complete depletion of the absorption region, to a value determined by the Shockley–Read–Hall generation-recombination mechanism.

We report on the investigations of focal plane arrays for mid-wave infrared radiation detection based on antimonide multilayers with InSb, Al x In 1 – x Sb, and InAs 1 – x Sb x absorption layers, including structures with InAlSb (InSb/InAlSb/InSb) and InAsSb (InAsSb/AlAsSb/InAsSb) barrier layers for optoelectronic systems and equipment. Photosensitive elements of different topologies have been fabricated. It has been demonstrated that wideband Al x In 1-x Sb and InAs 1 – x Sb x ternary alloys are an alternative to the narrowband InSb binary compound, since the photodiodes based on them exhibit lower dark currents and, consequently, low noise. The average values of detectivity D * and noise equivalent temperature difference for the photodetectors based on photosensitive element arrays of different topologies have been measured.

In recent years, there has been a rapid improvement in photonics products due to the use of multilayer heterostructures grown on the basis of advanced materials; designing the structure of a photosensitive element (PSE) to achieve the minimum dark current, which in turn leads to a change in generations of matrix photodetector modules (PDMs). Several different types of PDMs based on InSb epitaxial structures for the range of 3–5 μm, based on GaAs/AlGaAs QWIP-structures for the range 7.8–9.0 μm, and based on InGaAs XBn-structures for the range 0.9–1.7 μm were developed and investigated. The foreign analogs are shown, and the advantages given by the new capabilities offered by new detector technologies are considered.

In this paper, we report on the design, the fabrication, and performance of SWIR photomodules using sensitive two-dimensional arrays based on InGaAs-heterostructures. The de- sign of suggested InGaAs-heterostructure includes InAlAs wideband barrier layer and high sensitive absorber InGaAs layer which are increasing the uniformity and operability of focal plane array (FPA), so the number of defect elements are less than 0.5 %. The possibilities of spectral range expanding into short-wavelength to 0.5 μm and into long-wavelength to 2.2 μm regions have been considered. The operation principals of active-pulse system for 0.9–1.7 μm spectral range based on InGaAs 320256 FPA with 30 μm pitch have been presented. The investigations showed that the infrared gated-viewing system based on the InGaAs 320256 FPA provided a spatial resolution of 0,6 m.

Aspects of epitaxially grown indium antimonide (InSb) on InSb substrates (InSb-on-InSb) by molecular beam epitaxy (MBE) for the 2D focal plane arrays fabrication process have been described. The epitaxial growth offers possibility for complex structure production, and then such structures suppose more effective control of the thermal generation charge carriers as the detector temperature is raised above 80 K. Investigations of mid-wave infrared (MWIR) 320256 FPAs with 30 μm pitch and 640512 FPAs with 15 μm pitch based on InSb-on-InSb layers have shown high performance: the average detectivity at T = 77 K more than 21011 cmW-1Hz1/2, the average value of noise equivalent temperature difference (NETD) with a cold aperture of 60o at T = 77K was in the range of 10–20 mK. High quality thermal imaging images were obtained in real time mode.

Представлены результаты исследований матричных фотоприемных устройств (ФПУ) на основе тройных соединений InGaAs коротковолнового ИК диапазона спектра формата 320х256 элементов с шагом 30 мкм и 640х512 элементов с шагом 15 мкм, работающих в пассивном и активно-импульсном режимах реального времени [1]. Важной функциональной возможностью ФПУ формата 320х256 является функционирование в четырех режимах реального времени: пассивном 2D; активном 2D с заданной глубиной по дальности; активно-импульсном 3D (дальномерном); асинхронном бинарном для обнаружения внешних лазерных излучателей [2].

In the study, a new рBn-architecture based on a GaAsSb/AlAsSb/InAsSb heterostructure of III‒V group materials with an n-type AlAsSb barrier layer, an n-type InAsSb absorption layer, and a р-type GaAsSb collector layer, designed for detection of radiation in the mid-wavelength infrared range of 3.1–4.2 µm has been developed and investigated. The proposed structure has no valence band offset, which enables operation in a wide bias voltage range without depletion of the base n-type InAsSb active layer. The barrier in the conduction band, due to the presence of a wide-gap AlAsSb layer in the structure, is ∼1.0 eV, which is sufficient to eliminate the electron current component. The dark currents and performance of the рBn-structure have been analyzed, with the result that, at an operating temperature of Т ≈ 150 K and dark current density of J ≤ 6 × 10–10 A/cm2, the detectivity value reaches D* ≥ 2.5 × 1012 (cm W–1 Hz1/2).

The surface recombination rates for p -type HgCdTe layers with different dopant concentrations and trap densities N t are calculated. It is shown that, at the given initial parameters, the surface recombination rate S max lies in the range of 10–10 4 cm/s. The current sensitivity for p -type HgCdTe is simulated using the dependence of quantum efficiency in the approximation of large lifetimes τ n 0 and large diffusion lengths L n of minority charge carriers, taking into account the effect of the surface recombination rate.

UV visible-blind and solar-blind 320 × 256 photodiode arrays based on Al x Ga 1 – x N heteroepitaxial structures (AlGaN HES) and sensitive in the near-ultraviolet range of 0.2–0.4 μm have been created and studied. The AlGaN HES were grown by organometallic vapor deposition (MOCVD) and molecular beam epitaxy (MBE) on sapphire substrates. To reduce structural defects, the state of the surface and the surface layer of epipolished sapphire substrates was investigated, and a finishing technology was developed. UV FPAs in the AlGaN HES were produced by ion etching. The dark current components for AlGaN photodiodes were simulated. The main dark current components, such as generation–recombination, shunting leakage, hopping conductivity, and Poole–Frenkel components, are calculated. The possibility of achieving photoelectric parameters on the level of the best foreign counterparts is demonstrated .

Parameters of multi-row photodetectors (PDs) based on HgCdTe heteroepitaxial structures of different formats, including 288 × 4, 480 × 6, 576 × 4, and 576 × 6, with a step of 28 to 14 microns are studied. Owing to the choice of a N+/P-/р-architecture, PDs operate at elevated temperatures in the time delay and integration (TDI) mode with the implementation of the analog mode of TDI and the replacement of defective elements directly in the readout LSI. The PDs are capable of forming high-definition images of the 768 × 576 format at a frame rate of 50 Hz in real time. For the multi-row PDs, high photoelectric parameters were obtained: the detection capacity at the maximum of the spectral sensitivity D* ≥ 5 × 1012 cm W–1 Hz1/2 at temperatures Т~ 170–200 K and the number of working channels is not less than 99.0%.

The 320 × 256 focal plane arrays based on р + -B–n-N + tetralayer heterostructures with a wide-gap barrier layer have been investigated. The heterostructures with a narrow-gap n-InGaAs absorbing layer were grown by means of metalorganic vapor phase epitaxy on InP substrates. The band discontinuity between the In0.53Ga0.47As absorbing layer and the In0.52Al0.48As barrier layer is removed by growing a thin four-component n-AlInGaAs layer with the bandgap gradient variation. Delta-doped layers included into the heterostructures make it possible to lower the barrier in the valence band and eliminate the nonmonotonicity of energy levels. The experimental study of the dark current has been performed. It has been revealed that the average value of the dark current does not exceed 10 fA for the photodiode arrays with a pitch of 30 μm.

The temperature dependence of the minority charge carriers diffusion length in the active photosensitive layer of a matrix photodetector based on MCT heteroepitaxial structure grown by molecular beam epitaxy is studied.

SWIR ADP 320 × 256 FPAs based on p–i–n photodiodes in InGaAs heterostructures have been developed and investigated. The typical InGaAs/InP PIN heterostructures are formed by Metal Organic Vapor Phase Epitaxy (MOVPE) on n + type InP substrates. The InGaAs/InP PIN photodiodes performance have been estimated by measuring current-voltage characteristics. APD arrays are designed using a mesa-passivated avalanche photodiode device array of p–i–n junctions in heterostructure with common absorption and multiplication regions. The optimal operating point for managing avalanche application depended on various factors has been started at 15 V bias and the multiplication coefficient was of 2–4.

320 × 256 avalanche array photodetector on the basis ternary alloys of the A3B5 group with an InGaAs absorbing (in the band of 0.9–1.7 μm) layer and InAlAs barrier layer is studied. The array of 320 × 256 elements was fabricated in a nBp nanoheterostructure by the mesa technology. The number of imperfect elements, the dependence of the dark current on the bias voltage, and the avalanche gain factor are measured.