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The works examines the power adaptive control of back-gated planar transistor employing a novel super-self-alignment design. The availability of such back-gate provides additional freedom for the improvement of the transistor performance of higher switching speed and lower power consumption. Both of these two capabilities are investigated through the studies of transistor's output and transfer characteristics.

The context of SOI technology is briefly presented in terms of wafer fabrication, configuration/performance of SOI devices, and operation mechanisms in partially and fully depleted MOSFETs. Typical radiation effects, induced by single particles and cumulated dose, are evoked: BOX degradation, parasitic bipolar action, coupling effects, transistor latch, and back-channel conduction. The future of SOI is tentatively explored, by discussing the further scalability of SOI-MOSFETs as well as the innovating architectures proposed for the ultimate generations of SOI transistors.

THz response of AlGaAs/InGaAs/GaAs HEMT structure has been investigated. The structure consists of the serpentine chain of series connected HEMTs. The source of one is the drain for the subsequent transistor. Experiments have been showed THz response peculiarities of such structures and enhanced noise equivalent power.

Detection of terahertz radiation by GaAs transistor structures has been studied experimentally. The two types of samples under study included dense arrays of HEMTs and large-apertures detectors. Arrays consisted of parallel and series chains with asymmetric gate transistors for enhanced photoresponse on terahertz radiation. We investigated two types of wide-aperture detectors: grating gate detector, and single gate detector with bow-tie antenna. Wide-aperture detectors were symmetrical. Studies of transistor chains have shown that two essential features for this type of detector are the presence of asymmetry in the gate, and the type of connection between individual transistors themselves. Wide-aperture detectors have also been tested by narrow beams of terahertz radiation, which allows analyzing the role influence of individual parts of the detector for total sensitivity to terahertz excitation. The sensitivity and noise equivalent power of the detectors were evaluated.

Here we present a short introduction into physics of Dirac materials. In particular we review main physical properties of various two-dimensional crystals such as graphene, silicene, germanene and others. We comment on the origin of their buckled two-dimensional shape, and address the issues created by Mermin-Wagner theorem prohibiting the existence of strictly two-dimensional, flat crystals. Then we describe main ideas which were leading to the discovery of two and three-dimensional topological insulators and Weyl fermions. We describe some of their outstanding electronic properties which have been originating due to the existence of the Dirac gapless spectrum. We also compare simplest devices made of Dirac materials. Analogies and differences between Dirac materials and optics are also discussed.