Igor V. Marchishin

The absorption of terahertz radiation by a thin metal absorber in the bolometers of five different designs is analyzed. Main attention is paid to bolometers of three basic configurations: (i) conventional bolometers with a double-layer main optical cavity, (ii) conventional bolometers with an additional optical cavity, and (iii) inverted bolometers with an additional optical cavity. Analytical expressions that allow calculating the absorption spectra in all the considered bolometers are obtained. It is shown that conventional bolometers only with the main optical cavity made up of two dielectric layers, as well as conventional and inverted bolometers with both main and additional optical cavities, can have the absorptance close to unity in the terahertz range. At the same time, conventional terahertz bolometers are mainly selective, whereas inverted ones are broadband.

Electron transport in single GaAs quantum wells of widths from 22 to 46 nm with two populated quantum-confinement subbands ES and EAS is investigated at a temperature of T= 4.2 K in tilted magnetic...

Growth-related structural defects present on the surface of InAlAs layers grown by molecular beam epitaxy on InP(001) substrates influence the temperature dependences of the current–voltage...

This paper describes the design of readout integrated circuits (ROICs) for hybrid infrared focal plane arrays (IR FPAs). This work contains the estimation of the noise equivalent temperature difference (NETD) of IR FPAs based on frame and row integration of pixel signals in the spectral ranges of 8 to 14 and 3 to 5 μm. This paper also describes the development of ROICs for IR FPAs created with the use of mercury—cadmium—telluride (MCT) photodiodes and quantum well infrared photodetectors (QWIPs). The designed ROICs ensure the use of matrix and linear photodetector chips, including those with increased dark currents, in order to produce IR FPAs with temperature resolution corresponding to the world level of array analogs.

This paper presents the physical and technical principles of readout integrated circuit (ROIC) for reading and preprocessing focal plane array signals in the infrared spectral range 8–14 μm. The noise equivalent temperature difference of long-wavelength infrared focal plane arrays based on ROIC with frame integration of signals of multilayer quantum well structures is evaluated. The influence of technological limitations in silicon readout circuits for photo signals on the performance of IR focal plane arrays is analyze for a wide range of parameters of QWIP -based focal plane arrays and CMOS technology design rules.

This paper presents the results of a study of the scientific and engineering principles of the creation of silicon multiplexers intended for reading out and preprocessing photodetector signals in the IR ranges 8–14 and 3–5 μm. The noise equivalent temperature difference is estimated for far-IR photodetectors based on silicon multiplexers with linewise and framewise accumulation of signals from HgCdTe photodiodes (PDs). The features of how the structural–technological limitations in the silicon readout circuits affect the characteristics of the IR photodetectors are analyzed for a wide range of parameters of HgCdTe PDs and a wide range of technological design norms for fabricating silicon multiplexers.

Nonlinear magnetotransport of two-dimensional electrons in square antidot lattices prepared on the basis of selectively doped GaAs/AlAs heterostructures with the period that is much less than the electron mean free path in the initial GaAs quantum wells but is much larger than their Fermi wavelength has been studied. It has been shown that the character of the nonlinear transport of the two-dimensional electrons in the lateral lattices under study changes from classical to quantum with the decrease in the antidot radius. It has been found that the quantum lifetime increases in the magnetic field corresponding to the condition of equality of the cyclotron diameter of two-dimensional electrons and the antidot lattice period.

This paper discusses the process-design principles for creating hyperlarge-format mosaic photodetectors (MPDs), based on the butt-joining process of silicon chips with uncooled small-format microbolometer detector arrays (MBDAs). The basic unit is investigated and optimized for the process operations of laser scribing as part of the high-precision butt-joining process of chips in which the process part of the blind zone between the photosensitive edge elements of adjacent MBDA chips has a total size no greater than 30 μm. The design and layout are synthesized for 384×288-format silicon multiplexers, from which a 3072×576-format MPD fabricated using the butt-joining process developed here can provide better than 99% image-conversion efficiency for IR microbolometers and up to 100% for terahertz-range microbolometers.

This paper gives the parameters of 320 × 256 element long-wavelength infrared photodetectors fabricated by a new improved technology based on heteroepitaxial mercury-cadmium-tellur structures. In these photodetectors, the variation of the photodiode bias voltage over the area of the array is minimized; inefficient photodiode regions related to both hybridization and spike-shaped growth defects of epitaxial films are eliminated; the current-voltage characteristics of the diodes in the resulting photodetectors are homogeneous and are limited by the diffusion current component up to −400 mV. The dark current is 0.25–0.45 nA, and R ₀ A = (0.6–3) · 10² Ω · cm². The voltage sensitivity, the threshold irradiance, and the average NETD at the maximum sensitivity are 11.8 · 10⁸ V/W, 3.7 · 10⁻⁸ W/cm², and 26.8 mK, respectively. The percentage of defective elements is 1.5%.