Analysis of the nBn-type barrier structures for infrared photodiode detectors

Modern trends in the technology of CdxHg1–xTe-based photosensitive barrier structures for the middle and far infrared bands, which can operate at near-room temperatures, are analyzed. Main approaches to solving the problem of increasing the photodiode-detector operating temperature have been considered and analyzed

Temperature and field dependences of parameters of the equivalent circuit elements of MIS structures based on MBE n-Hg0.775Cd0.225Te in the strong inversion mode

A technique is proposed for the determining the parameters of the equivalent circuit elements in strong inversion mode using the measurement results of the admittance of MIS structures based on n-Hg0.775Cd0.225Te grown by molecular beam epitaxy. It is shown that at 77 K and frequencies above 10 kHz, the capacitancevoltage characteristics of MIS structures based on n-Hg0.775Cd0.225Te with a near-surface graded gap layer have a high-frequency behavior with respect to the recharge time of surface states located near the Fermi level of intrinsic semiconductor. It is established that the electron concentration in the near-surface graded-gap layer exceeds an average concentration found by the Hall method by more than 2 times. The proposed technique was used for determining the temperature dependences of the insulator capacitance, capacitance and differential resistance of the space-charge region, and capacitance of the inversion layer in MIS structures based on n-Hg0.775Cd0.225Te without a graded-gap layer. The temperature and voltage dependences of the parameters of the equivalent circuit elements in strong inversion are calculated. The results of calculation are qualitatively consistent with the results obtained from the measurements of the admittance

Generalized Muller-Kern formula for equilibrium thickness of a wetting layer with respect to the dependence of the surface energy of island facets on the thickness of the 2D layer

Experimental results indicate a particular importance of such a value as the equilibrium thickness of the wetting layer during epitaxial growth according to the Stranski–Krastanow mechanism in systems with a lattice mismatch. In this paper the change in free energy during the transition of atoms from the wetting layer to the island in such systems is considered. Recent experimental results also show that the surface energy of the island's facets depends upon the thickness of the deposited material. So, in this paper the equilibrium thickness of the wetting layer, at which transition from 2D to 3D growth becomes energetically favorable, is calculated with the assumption that the specific energy of the island's facets depends upon the wetting layer thickness. In this approximation a new generalized Muller–Kern formula is obtained. As an illustration of the proposed method, an example of a numerical calculation according to the new formula for the material system of germanium on a silicon (001) surface is given. The result for the found equilibrium thickness of the wetting layer is rather unexpected since it differs from the value obtained in the bounds of the traditional Muller–Kern model

Kinetics of epitaxial formation of nanostructures by Frank-van der Merwe, Volmer-Weber and Stranski-Krastanow growth modes

Nowadays, two-dimensional crystals (2D materials) and structures with quantum dots (0D materials) are considere

Changes in the electro-physical properties of MCT epitaxial films affected by a plasma volume discharge induced by an avalanche beam in atmospheric-pressure air

In this paper the influence of the plasma volume discharge of nanosecond duration formed in a non-uniform electric field at atmospheric pressure on samples of epitaxial films HgCdTe (MCT) films are discussed. The experimental data show that the action of pulses of nanosecond volume discharge in air at atmospheric pressure leads to changes in the electrophysical properties of MCT epitaxial films due to formation of a near-surface high- conductivity layer of the n-type conduction. The preliminary results show that it is possible to use such actions in the development of technologies for the controlled change of the properties of MCT