Three identified possible directions for the artificial realization of consciousness are considered: 1) materialistic; 2) idealistic; 3) hybrid. In principle, this is the most difficult task of artificial intelligence. The most promising approaches to the artificial realization of consciousness are distinguished in the directions. As a result of the analysis, a hypothesis was formulated about the possibility of such an implementation. Moreover, this can be, in principle, carried out within the framework of the three directions noted, but approximately. At the same time, if we consider the consciousness of a particular person, then in an artificial analogue, in essence, everything that is stored in the brain of this person should be reproduced, and this is a task offantastic complexity. The author sees a possible solution of the problem by copying information from the corresponding brain. The question of the dynamic change of consciousness as a result of human interaction with the external environment will also be very difficult.

At present, a great deal of interest is observed in devices based on two-dimentional (2D) materials, especially graphene, in the field of micro- and nanoelectronics. Graphene has robust hoheycomb lattice structure and unique properties such as ambipolarity, high carrier mobility, high conductivity. Nevertheless the properties of mono- and bilayer graphene are different. A significant difference in electrical characteristics of field-effect transistors (FETs) based on mono- and bilayer graphene was shown in few experimental works [1-3]. Note, that FET on bilayer graphene has demonstrated improved characteristics in comparison to FET on monolayer graphene [1,4,5]. Therefore a necessity to create models specifically for FETs on bilayer graphene appears. A tunable band gap is observed in the FET, when a perpendicular electrical field is applied to the bilayer graphene channel [6]. In the paper a quantum drift-diffusion model of FETs based on bilayer graphene is proposed. The model is a combination of electrical and physical models [7]. The mechanism of carrier transport along the bilayer graphene channel is considered. The electrostatic potential of the transistor channel is defined according to the band gap. Simulation of graphene dual-gate FET with channel length 4 µm is performed using the proposed model. Calculation of electrostatic potential of the investigated device structure was carried out. A good agreement with experimental data has been obtained for output characteristics of FETs based on monolayer graphene [8] using the developed model for this case. Different design parameters of FETs such as channel length, channel width, thickness of top- and back-gate dielectrics are used in the models. The proposed models of different FETs were included in the nanoelectronic devices simulation system NANODEV [9] developed at the BSUIR since 1995.

A review of the author’s original studies related to the human brain as an object of electronics is given. The following issues are considered: the proposed full electronic interpretation of the functioning of the brain and a complex hierarchical approach to studying the brain; human consciousness; prospects and problems of creating a supermind; and prospects for the use of nanoelectronics, nanomaterials, and nanotechnologies in studying the human brain.

The development of field-effect transistors (FETs), resonant-tunneling diodes (RTDs), vertical heterostructures and other device structures on the basis of 2D materials is one of the important tasks for producing a new element base for micro and nanoelectronics. The wave function formalism was applied in the development of numerical model of vertical heterostructures based on 2D materials [1, 2]. Combined self-consistent models [3, 4] were adapted for the case of taking into account vertical transport in the conduction band. The influence of various factors on the electric characteristics of the vertical heterostructures based on graphene, h-BN and MoS2 was investigated with the use of the developed model. The IVcharacteristics of such structures were calculated for different number of layers of 2D materials that forms potential barriers and quantum wells. Comparison of the results of simulation of the investigated structures is carried out. A numerical combined model based on a self-consistent numerical solution of the Schrödinger and Poisson equations in the active region of the device was used to calculate the IV-characteristics of GaN/AlGaN-based RTDs with vertical transport [5, 6]. The proposed model was used to study the effect of the aluminum concentration in the barriers on the IV-characteristics of the considered RTDs. Developed quantum drift-diffusion model of FET based on monolayer graphene was described in detail [7, 8]. The model is based on quantum drift-diffusion approximation of carrier transport. Graphene channel is located between topand back-gate dielectrics. With the use of the model simulation of dual-gate FET with channel width 18 μm was considered. A good agreement with experimental data was obtained for number of applied voltages. Adequacy of the model is confirmed by these calculations. The programs realizing the proposed models were included in the nanoelectronic devices simulation system developed at the BSUIR since 1995 [9, 10].

Field-effect graphene transistors (FGTs) based on single-layer graphene using the developed simplified combined self-consistent model are simulated. It is used to compare the results of calculating the current–voltage ( I–V ) characteristics of five devices with the same geometric parameters with different materials of the gate dielectric of the upper gate. The influence of the thickness of the dielectrics of the upper and lower gates on the transfer I–V characteristic of a dual-gate FGTs is analyzed

The prospects and problems of supermind creation are estimated.The previously proposed full electronic interpretation of brain functioning and the theory of human consciousness are the methodological basis of consideration.

Описана разработанная комбинированная численная самосогласованная модель для расчета электрических характеристик многобарьерных наноструктур на основе двухслойного графена. С ее использованием рассчитаны вольт-амперные характеристики (ВАХ) трех-, четырех- и пятибарьерных резонансно-туннельных диодов (РТД) на основе графена на подложке диоксида кремния (SiO2). Исследова- но влияние ширин барьеров и квантовых ям на ВАХ трехбарьерных РТД на основе графена на подложке SiO2. Рассмотрены структуры с симметричными барьерами и ямами. Установлено, что увеличение ширин квантовых ям приводит к существенному уменьшению плотностей пиковых токов и токов долины, а увеличение ширин потен- циальных барьеров приводит к незначительному уменьшению плот- ности тока первого пика, а также к увеличению плотностей токов второго пика и долины.Рассчитаны также зависимости плотностей токов от напряжений для РТД с четырьмя и пятью барьерами на основе гексагонального нитрида бора (h-BN) и диоксида кремния (SiO2) и квантовыми ямами на основе двухслойного графена. Проведено сравнение ВАХ исследованных РТД. Абрамов И. И., Коломейцева Н. В., Лабунов В. А., Романова И. А., Щербакова И. Ю. Численное моделирование трехбарьерных резо- нансно-туннельных диодов на основе графена. Ural Radio Engineering Journal. 2019;3(4):343–355. DOI: 10.15826/urej.2019.3.4.001

The development of field-effect transistors (GFETs), resonant-tunneling diodes (RTDs) and other device structures on the basis of graphene is one of the important tasks for producing a new element base for micro- and nanoelectronics. The report presents the simulation results of the GFET based on monolayer graphene in various operating modes, as well as the RTD based on bilayer graphene and carbon nanotubes. The main model of GFET [1, 2] was developed on the basis of the quantum drift-diffusion model. It is a combination of electrical and physical models. According to the model the electrostatic potential of the channel is calculated selfconsistently. The report describes the modification of the model for the case of GFET transfer characteristics calculation. The optimization method of dichotomy is used for this purpose. A satisfactory agreement with the experimental data not only of the output, but also of the transfer characteristics of a single- and dual-gate GFET was obtained with the use of the modified model. In the report, the influence of various factors on the characteristics of the investigated GFET was analyzed with the use of the model. The wave function formalism was applied in the development of numerical models of resonant-tunneling device structures based on carbon nanomaterials. It was also taken into account that RTD includes not only nanostructures (active regions) but also extended (passive) regions. Combined self-consistent models of RTD based on graphene and carbon nanotubes [3,4] were developed in accordance with quantum-mechanical and semiclassical approaches. The influence of various factors (height and shape of potential barriers, contact areas extension) on the characteristics of the RTD based on bilayer graphene was investigated with the use of the developed models. The programs realizing the models of GFET and graphene-based RTD were included in the nanoelectronic devices simulation system developed at the BSUIR since 1995 [5,6].

АннотацияОписана разработанная комбинированная численная самосогласованная модель для расчета электрических характеристик многобарьерных наноструктур на основе двухслойного графена.С ее использованием рассчитаны вольт-амперные характеристики (ВАХ) трех-, четырех-и пятибарьерных резонансно-туннельных диодов (РТД) на основе графена на подложке диоксида кремния (SiO 2 ).Исследовано влияние ширин барьеров и квантовых ям на ВАХ трехбарьерных РТД на основе графена на подложке SiO 2 .Рассмотрены структуры с симметричными барьерами и ямами.Установлено, что увеличение ширин квантовых ям приводит к существенному уменьшению плотностей пиковых токов и токов долины, а увеличение ширин потенциальных барьеров приводит к незначительному уменьшению плотности тока первого пика, а также к увеличению плотностей токов второго пика и долины.Рассчитаны также зависимости плотностей токов от напряжений для РТД с четырьмя и пятью барьерами на основе гексагонального нитрида бора (h-BN) и диоксида кремния (SiO 2 ) и квантовыми ямами на основе двухслойного графена

Graphene is a nanomaterial that due to unique properties has attracted great interest for various applications, in particular, for development of nanoelectronic devices. In the paper the graphene field-effect transistors (GFET) and resonant tunneling diodes (RTD) are analyzed with the use of proposed models. First, simulation of dual-gate field-effect transistor based on monolayer graphene with the use of proposed combined model is considered. In the model the following important factors such as quantum capacitance, hole and electron mobility difference, drain and source resistances are taken into account. Investigations of dependence of a drain current on drain voltage for various top-gate-to-source voltages are performed. Influence of channel length, source and drain resistances on output characteristics of the device is analyzed. Comparison of calculation results with simulation ones obtained with the known models was carried out. Secondly, simulation of graphene-based nanostructures on hexagonal boron nitride, silicon carbide and silicon dioxide substrates was performed using proposed self-consistent numerical model, based on effective wave function formalism. The developed models in detail were described in our previous works. The possibility of using a proposed self-consistent model for double- and triple-barrier graphene-based RTD simulation was illustrated. As well as it was investigated the influence of different parameters on IV-characteristics of graphene-based RTDs. It was shown that it is necessary to take into account extended (passive) regions for adequate simulation of these devices.

Layered nanoheterostructures of nanoporous anodic aluminum oxide / metal-polymer coordination compound / clusters of few-walled carboxylated carbon nanotubes type are proposed. Their biosensibility and biocompatibility are shown. ECIS-impedance sensor coated with such nanoheterostructures operates on quantum effects of the spontaneous polarization and the quantization of the Maxwell-Wagner polarization and detects structural organization and intercellular communication in the cell monolayer of C6 rat glioma.

The simulation results of different devices based on carbon nanotubes (CNT) and graphene are described in the paper.The combined numerical model of hybrid integrated structures including resonant tunneling diode and field-effect transistor (RTD-FET) is proposed. Simulation of RTD-FET based on CNT of different types (chirality) was realized with the use of the developed model.The technique of express simulation of nanoradio based on CNT of the type I (based on only single CNT) and of the type II (hybrid radio) is developed. Proposed models can be used for calculation of nanoradio characteristics such as: 1) resonant frequency of CNT; 2) oscillation amplitude of CNT; 3) CNT IV-characteristics depending on different factors. Results of device simulation based on single-wall and multi-wall CNT are given in the paper.IV-characteristics of nanoscale resonant tunneling structure based on graphene-on-SiC were calculated. As well as it was investigated the influence of different parameters on the electrical characteristic of graphene-based nanostructures.

Nanoscale structures based on carbon materials are simulated using the developed numerical models. A functionally integrated structure combining resonant tunneling diode and field-effect transistor based on single carbon nanotube (RTD-FET) is studied. It is found that RTD-FET will have significantly different N-shaped current-voltage characteristics depending on the chirality of the used nanotube. Current-voltage characteristics of a resonant tunneling nanostructure based on graphene are also calculated.

Modification of an express engineering method for simulation of nanoelectromechanical system (NEMS) such as nanoradio based on multi-walled carbon nanotubes (CNT) is proposed. Calculations of NEMS including two and three electrodes are carried out. Firstly, the influence of a distance between CNT top and an anode on nanoradio IV-characteristics is shown. Secondly, the influence of a distance between CNT and a bottom electrode on a normalized frequency shift of radio receivers is illustrated.

Modification of an express engineering method for simulation of nanoradio based on carbon nanotubes was proposed. Influence of nanoelectromechanical system parameters on nanoradio IV-characteristics was shown. Calculation of demodulation current of amplitude modulated (AM) signals was also made.

The influence of potential barriers width deviation on IV-characteristics of RTD is investigated using the suggested modified two-band combined model. A multi-island structure was simulated using a modified model in case of account of spatial quantization on islands of single-electron devices. It enables one to achieve a satisfactory agreement of simulation results with experimental data.

In the paper the nanoelectronic devices based on the resonant tunneling effect are analyzed. In particular, the currentvoltage characteristics of resonant-tunneling diodes (RTD’s) based on Si/Ge, Si/SiGe heterostructures and based on carbon nanotubes (CNT) are calculated using proposed models. The first combined two-band model [1, 2] for calculation of RTD characteristics with account of valence band influence is modified for the case of account of quantum well width deviation. The combined numerical model of RTD is based on the self-consistent solution of Poisson and Schrödinger equations. The developed model provides good agreement with experimental data at room temperature. In the paper the results of simulation according to the proposed model for double-barrier Si/Ge, Si/SiGe RTD’s are obtained. The second and third models for RTD based on CNT are presented. The second model is a simple analytical one. The results of simulation according to this model for devices based on CNT are presented for different values of Fermi energy level. The Fermi energy level depends on the material used for contact system. The third model is a self-consistent one. Comparison of analytical model and self-consistent one is presented. A good agreement of simulation results was obtained only at small voltages. IV-characteristics with larger values of peak current and peak voltages were obtained with the use of the third numerical model. Thus the second model can be only used for rough estimations of characteristics of RTD based on CNT.