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Various samples of multisectoral high‐pressure high‐temperature (HPHT) single‐crystal diamond plate (IIa type) (4 × 4 × 0.53 mm) are tested for particle detection applications. The samples are investigated by X‐ray diffractometry, photoluminescence spectroscopy, Raman spectroscopy, Fourier‐transform infrared, and visible/ultraviolet (UV) absorption spectroscopy. High crystalline perfection and low impurity concentration (in the {100} growth sector) are observed. To investigate detector parameters, circular 1.0 and 1.5 mm diameter Pt Schottky barrier contacts are created on {111} and {100} growth sectors. On the backside, a Pt contact (3.5 × 3.5 mm) is produced. The {100} growth sector is proved to be a high‐quality detector: the full width at half maximum energy resolution is 0.94% for the 5.489 MeV 226Ra α‐line at an operational bias of +500 V. Therefore, it is concluded that the HPHT material {100} growth sector is used for radiation detector production, whose quality is not worse than the chemical vapor deposition method or specially selected natural diamond detectors.

Computer simulations were performed to increase the quantum efficiency of LED by optimizing the nanoheterostructure (NH). Furthermore, the InGaN and AlGaP NHs for LEDs were optimized. On the basis of the optimum NH, ways to further increase the efficiency and the influence of impurities and indium atoms doped into barriers between quantum wells were investigated. The optimum impurity and indium atom concentrations to achieve higher flux were determined.

By the original method, using the sequential high-purity Mn and Sb metals evaporation, followed by annealing under high vacuum conditions, MnSb semiconductor films were synthesized. It is shown that the high chemical activity of nanostructured Mn and Sb films significantly reduces the manganese antimonide evaporation temperature. Films are p- type and have a high charge carriers mobility.

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The a-GaN films were successfully grown on the r-sapphire substrate by MOCVD method. The structure of V-defects was investigated by AFM and SEM. The dependence of V-defects density on growth temperature of a-GaN film at a constant hydrogen flow through a TEG source was studied. The influence of V/III ratio on V-defects structure was investigated. Methods of V-defects density minimisation were purposed.

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