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Progress in electronics is limited by power dissipation constraints. Ferroelectric materials with a negative capacitance could help to overcome these limits. Especially, HfO₂ and ZrO₂ based ferroelectrics are promising for negative capacitance electronics due to their compatibility with modern transistor manufacturing processes. Recently, first negative capacitance transistors have been demonstrated. However, further investigations on the microscopic origin of negative capacitance in HfO₂- and ZrO₂-based ferroelectrics are needed. Lastly, opportunities for negative capacitance beyond transistors are discussed.

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.

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.

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.

During these last years, the substantially biological field effect transistors (BioFET) are one of the most abundant classes of electronic sensors for biomolecular detection. The determination of glucose levels using these biosensors, especially in the medical diagnosis and food industries, is gaining popularity. Among them, ion-sensitive field effect transistor (ISFET) is considered one of the most intriguing approaches in electrical biosensitivity technology. The glucose sensor ISFET detects the glucose molecule by catalyzing glucose to gluconic acid and hydrogen peroxide in the presence of oxygen. In this paper, first of all we examine some of the main advantages in this field, the perspective of applications and the main issues in order to stimulate a broader interest in the development of biosensors based on ISFET and to extend their applications for a reliable and sensitive glucose analysis. Thereafter, a biosensor with field effect sensitive to the ions for the detection of glucose is modeled analytically. In the proposed model, the glucose concentration is presented according to the gate voltage. The simulated data show that the analytical model can be used with an electrochemical glucose sensor to predict mechanism’s behavior of detection in the biosensors.

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.

An analytical model of the channel electron energy distribution in an on-state GaN transistor has been proposed based on the assumption that drift velocities of channel electrons obey the two-dimensional Maxwell–Boltzmann distribution. The validity of such an assumption was confirmed by Monte Carlo simulation. It was found that there could be a larger number of high-energy channel electrons whose energy is higher than the intervalley energy between ${\mathrm{\Gamma }}_1$ and ${\mathrm{\Gamma }}_2$ valleys in a GaN transistor with a high electron temperature. The fraction of hot electrons with its energy higher than the intervalley energy between ${\mathrm{\Gamma }}_1$ and ${\mathrm{\Gamma }}_2$ valleys to the total channel electrons can easily reach 50% when the electron temperature is higher than 3000 K. Such an electron temperature in a GaN transistor had been determined in experiments. Thus, hot electrons in the ${\mathrm{\Gamma }}_1$ valley can transit into ${\mathrm{\Gamma }}_2$ valleys. It suggests that intervalley transitions could be one possible physical origin of the abrupt change in the source−drain current in GaN devices. The proposed model can well explain how an abrupt change in the source–drain current in GaN transistor experiments depends on the voltage-dependent gate, the trap, etc.

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.